chore: enable Ukrainian locale on main

When an extension's preferred output isn't .m4a, downloaded M4A streams
are now automatically converted to FLAC via FFmpeg instead of being
preserved. This applies to both SAF and non-SAF download paths.

.github/workflows/release.yml

@@ -164,13 +164,18 @@ jobs:
           path: build/app/outputs/flutter-apk/SpotiFLAC-*.apk
 
   build-ios:
-    runs-on: macos-latest
+    runs-on: macos-15
     needs: get-version # Only depends on version, NOT android build!
 
     steps:
       - name: Checkout repository
         uses: actions/checkout@v6
 
+      - name: Select Xcode 26.1.1
+        run: |
+          sudo xcode-select -s /Applications/Xcode_26.1.1.app
+          xcodebuild -version
+
       - name: Setup Go
         uses: actions/setup-go@v6
         with:

README.md

@@ -168,7 +168,7 @@ Interested in contributing? Check out the [Contributing Guide](CONTRIBUTING.md)
 |---|---|---|---|---|
 | [hifi-api](https://github.com/binimum/hifi-api) | [music.binimum.org](https://music.binimum.org) | [qqdl.site](https://qqdl.site) | [squid.wtf](https://squid.wtf) | [spotisaver.net](https://spotisaver.net) |
 | [dabmusic.xyz](https://dabmusic.xyz) | [AfkarXYZ](https://github.com/afkarxyz) | [LRCLib](https://lrclib.net) | [Paxsenix](https://lyrics.paxsenix.org) | [Cobalt](https://cobalt.tools) |
-| [qwkuns.me](https://qwkuns.me) | [SpotubeDL](https://spotubedl.com) | [Song.link](https://song.link) | [IDHS](https://github.com/sjdonado/idonthavespotify) | |
+| [qwkuns.me](https://qwkuns.me) | [SpotubeDL](https://spotubedl.com) | [Song.link](https://song.link) | [IDHS](https://github.com/sjdonado/idonthavespotify) | [Monochrome](https://monochrome.tf) |
 
 ---
 

android/app/build.gradle.kts

@@ -20,6 +20,10 @@ android {
     compileSdk = flutter.compileSdkVersion
     ndkVersion = flutter.ndkVersion
 
+    buildFeatures {
+        buildConfig = true
+    }
+
     compileOptions {
         isCoreLibraryDesugaringEnabled = true
         sourceCompatibility = JavaVersion.VERSION_17
@@ -57,6 +61,18 @@ android {
     }
 
     buildTypes {
+        getByName("debug") {
+            ndk {
+                debugSymbolLevel = "FULL"
+            }
+        }
+
+        getByName("profile") {
+            ndk {
+                debugSymbolLevel = "FULL"
+            }
+        }
+
         release {
             // For local builds: use release signing if key.properties exists
             // For CI builds: APK is signed by GitHub Action after build
@@ -71,6 +87,9 @@ android {
                 getDefaultProguardFile("proguard-android-optimize.txt"),
                 "proguard-rules.pro"
             )
+            ndk {
+                debugSymbolLevel = "FULL"
+            }
         }
     }
     

android/app/src/main/AndroidManifest.xml

@@ -86,6 +86,20 @@
                 <category android:name="android.intent.category.BROWSABLE" />
                 <data android:scheme="https" android:host="music.youtube.com" />
             </intent-filter>
+
+            <!-- Extension OAuth (PKCE) redirect: spotiflac://callback?code=...&state=<extension_id> -->
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+                <data android:scheme="spotiflac" android:host="callback" />
+            </intent-filter>
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+                <data android:scheme="spotiflac" android:host="spotify-callback" />
+            </intent-filter>
         </activity>
 
         <!-- Download Service -->
@@ -94,24 +108,6 @@
             android:exported="false"
             android:foregroundServiceType="dataSync" />
 
-        <!-- Audio playback service for media notification / background audio -->
-        <service
-            android:name="com.ryanheise.audioservice.AudioService"
-            android:exported="true"
-            android:foregroundServiceType="mediaPlayback">
-            <intent-filter>
-                <action android:name="android.media.browse.MediaBrowserService" />
-            </intent-filter>
-        </service>
-
-        <receiver
-            android:name="com.ryanheise.audioservice.MediaButtonReceiver"
-            android:exported="true">
-            <intent-filter>
-                <action android:name="android.intent.action.MEDIA_BUTTON" />
-            </intent-filter>
-        </receiver>
-
         <!-- flutter_local_notifications receivers -->
         <receiver android:exported="false" android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationReceiver" />
         <receiver android:exported="false" android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationBootReceiver">

android/app/src/main/kotlin/com/zarz/spotiflac/MainActivity.kt

@@ -4,6 +4,7 @@ import android.app.Activity
 import android.content.Intent
 import android.net.Uri
 import android.os.Build
+import android.os.Bundle
 import androidx.activity.OnBackPressedCallback
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.documentfile.provider.DocumentFile
@@ -307,8 +308,40 @@ class MainActivity: FlutterFragmentActivity() {
         }
     }
 
+    private fun forceFilenameExt(name: String, outputExt: String): String {
+        val normalizedExt = normalizeExt(outputExt)
+        if (normalizedExt.isBlank()) return sanitizeFilename(name)
+
+        val safeName = sanitizeFilename(name)
+        val lower = safeName.lowercase(Locale.ROOT)
+        val knownExts = listOf(".flac", ".m4a", ".mp3", ".opus", ".lrc")
+        for (knownExt in knownExts) {
+            if (lower.endsWith(knownExt)) {
+                return safeName.dropLast(knownExt.length) + normalizedExt
+            }
+        }
+        return safeName + normalizedExt
+    }
+
     private fun sanitizeFilename(name: String): String {
-        return name.replace(Regex("[\\\\/:*?\"<>|]"), "_").trim()
+        var sanitized = name
+            .replace("/", " ")
+            .replace(Regex("[\\\\:*?\"<>|]"), " ")
+            .filter { ch ->
+                val code = ch.code
+                !((code < 0x20 && ch != '\t' && ch != '\n' && ch != '\r') ||
+                    code == 0x7F ||
+                    (Character.isISOControl(ch) && ch != '\t' && ch != '\n' && ch != '\r'))
+            }
+            .trim()
+            .trim('.', ' ')
+
+        sanitized = sanitized
+            .replace(Regex("\\s+"), " ")
+            .replace(Regex("_+"), "_")
+            .trim('_', ' ')
+
+        return if (sanitized.isBlank()) "Unknown" else sanitized
     }
 
     private fun sanitizeRelativeDir(relativeDir: String): String {
@@ -368,6 +401,43 @@ class MainActivity: FlutterFragmentActivity() {
         return current
     }
 
+    private fun createOrReuseDocumentFile(
+        parent: DocumentFile,
+        mimeType: String,
+        fileName: String
+    ): DocumentFile? {
+        val safeFileName = sanitizeFilename(fileName)
+        if (safeFileName.isBlank()) return null
+
+        synchronized(safDirLock) {
+            val existing = parent.findFile(safeFileName)
+            if (existing != null && existing.isFile) {
+                return existing
+            }
+
+            val created = parent.createFile(mimeType, safeFileName) ?: return null
+            val createdName = created.name ?: safeFileName
+            if (createdName == safeFileName) {
+                return created
+            }
+
+            // SAF can auto-rename to "name (1)" when another writer wins the race
+            // between findFile() and createFile(). Prefer the exact sibling if it
+            // appeared, and discard the duplicate document we just created.
+            val winner = parent.findFile(safeFileName)
+            if (winner != null && winner.isFile) {
+                if (winner.uri != created.uri) {
+                    try {
+                        created.delete()
+                    } catch (_: Exception) {}
+                }
+                return winner
+            }
+
+            return created
+        }
+    }
+
     private fun resetSafScanProgress() {
         synchronized(safScanLock) {
             safScanProgress = SafScanProgress()
@@ -599,12 +669,12 @@ class MainActivity: FlutterFragmentActivity() {
 
     private fun buildSafFileName(req: JSONObject, outputExt: String): String {
         val provided = req.optString("saf_file_name", "")
-        if (provided.isNotBlank()) return sanitizeFilename(provided)
+        if (provided.isNotBlank()) return forceFilenameExt(provided, outputExt)
 
         val trackName = req.optString("track_name", "track")
         val artistName = req.optString("artist_name", "")
         val baseName = if (artistName.isNotBlank()) "$artistName - $trackName" else trackName
-        return sanitizeFilename(baseName) + outputExt
+        return forceFilenameExt(baseName, outputExt)
     }
 
     private fun errorJson(message: String): String {
@@ -918,8 +988,7 @@ class MainActivity: FlutterFragmentActivity() {
         val targetDir = ensureDocumentDir(treeUri, relativeDir)
             ?: return errorJson("Failed to access SAF directory")
 
-        val existingFile = targetDir.findFile(fileName)
-        val document = existingFile ?: targetDir.createFile(mimeType, fileName)
+        var document = createOrReuseDocumentFile(targetDir, mimeType, fileName)
             ?: return errorJson("Failed to create SAF file")
 
         val pfd = contentResolver.openFileDescriptor(document.uri, "rw")
@@ -944,16 +1013,34 @@ class MainActivity: FlutterFragmentActivity() {
                 ) {
                     try {
                         val srcFile = java.io.File(goFilePath)
-                        if (srcFile.exists() && srcFile.length() > 0) {
-                            contentResolver.openOutputStream(document.uri, "wt")?.use { output ->
-                                srcFile.inputStream().use { input ->
-                                    input.copyTo(output)
-                                }
-                            }
-                            srcFile.delete()
+                        if (!srcFile.exists() || srcFile.length() <= 0) {
+                            throw IllegalStateException("extension output missing or empty: $goFilePath")
                         }
+                        val actualExt = normalizeExt(srcFile.extension)
+                        if (actualExt.isNotBlank() && actualExt != outputExt) {
+                            val actualFileName = buildSafFileName(req, actualExt)
+                            val actualMimeType = mimeTypeForExt(actualExt)
+                            val replacement = createOrReuseDocumentFile(
+                                targetDir,
+                                actualMimeType,
+                                actualFileName,
+                            )
+                                ?: throw IllegalStateException("failed to create SAF output with actual extension")
+                            if (replacement.uri != document.uri) {
+                                document.delete()
+                                document = replacement
+                            }
+                        }
+                        contentResolver.openOutputStream(document.uri, "wt")?.use { output ->
+                            srcFile.inputStream().use { input ->
+                                input.copyTo(output)
+                            }
+                        } ?: throw IllegalStateException("failed to open SAF output stream")
+                        srcFile.delete()
                     } catch (e: Exception) {
+                        document.delete()
                         android.util.Log.w("SpotiFLAC", "Failed to copy extension output to SAF: ${e.message}")
+                        return errorJson("Failed to copy extension output to SAF: ${e.message}")
                     }
                 }
                 respObj.put("file_path", document.uri.toString())
@@ -1931,9 +2018,54 @@ class MainActivity: FlutterFragmentActivity() {
     // We handle these URLs ourselves via receive_sharing_intent + ShareIntentService.
     override fun shouldHandleDeeplinking(): Boolean = false
 
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        handleExtensionOAuthIntent(intent)
+    }
+
     override fun onNewIntent(intent: Intent) {
         super.onNewIntent(intent)
         setIntent(intent)
+        handleExtensionOAuthIntent(intent)
+    }
+
+    /**
+     * Deliver Spotify (or other) OAuth authorization code to the extension runtime
+     * and run its token exchange (e.g. completeSpotifyLogin). State must be the extension id.
+     */
+    private fun handleExtensionOAuthIntent(intent: Intent?) {
+        val uri = intent?.data ?: return
+        if (!uri.scheme.equals("spotiflac", ignoreCase = true)) {
+            return
+        }
+        val host = (uri.host ?: "").lowercase(Locale.US)
+        val path = (uri.path ?: "").lowercase(Locale.US)
+        val isCallback =
+            host == "callback" ||
+                host == "spotify-callback" ||
+                path.contains("callback")
+        if (!isCallback) {
+            return
+        }
+        val code = uri.getQueryParameter("code")?.trim().orEmpty()
+        if (code.isEmpty()) {
+            return
+        }
+        val extId = uri.getQueryParameter("state")?.trim().orEmpty()
+        if (extId.isEmpty()) {
+            android.util.Log.w("SpotiFLAC", "Extension OAuth redirect missing state (extension id)")
+            return
+        }
+        intent.data = null
+        scope.launch(Dispatchers.IO) {
+            try {
+                Gobackend.setExtensionAuthCodeByID(extId, code)
+                val json = Gobackend.invokeExtensionActionJSON(extId, "completeSpotifyLogin")
+                android.util.Log.i("SpotiFLAC", "Extension OAuth complete for $extId: $json")
+            } catch (e: Exception) {
+                android.util.Log.w("SpotiFLAC", "Extension OAuth failed: ${e.message}")
+            }
+        }
     }
 
     override fun onDestroy() {
@@ -1949,6 +2081,7 @@ class MainActivity: FlutterFragmentActivity() {
 
     override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
         super.configureFlutterEngine(flutterEngine)
+        Gobackend.setAppVersion(BuildConfig.VERSION_NAME)
 
         // Always-enabled back callback to ensure back presses reach Flutter.
         // Nested tab navigators can incorrectly set frameworkHandlesBack(false),
@@ -2133,7 +2266,6 @@ class MainActivity: FlutterFragmentActivity() {
                                 result.error("saf_pending", "SAF picker already active", null)
                                 return@launch
                             }
-                            pendingSafTreeResult = result
                             val intent = Intent(Intent.ACTION_OPEN_DOCUMENT_TREE)
                             intent.addFlags(
                                 Intent.FLAG_GRANT_READ_URI_PERMISSION or
@@ -2141,7 +2273,24 @@ class MainActivity: FlutterFragmentActivity() {
                                     Intent.FLAG_GRANT_PERSISTABLE_URI_PERMISSION or
                                     Intent.FLAG_GRANT_PREFIX_URI_PERMISSION
                             )
-                            safTreeLauncher.launch(intent)
+                            val resolver = intent.resolveActivity(packageManager)
+                            if (resolver == null) {
+                                result.error("saf_unavailable", "No folder picker available on this device", null)
+                                return@launch
+                            }
+                            pendingSafTreeResult = result
+                            try {
+                                android.util.Log.i("SpotiFLAC", "Launching SAF picker via $resolver")
+                                safTreeLauncher.launch(intent)
+                            } catch (e: Exception) {
+                                pendingSafTreeResult = null
+                                android.util.Log.e("SpotiFLAC", "Failed to launch SAF picker: ${e.message}", e)
+                                result.error(
+                                    "saf_launch_failed",
+                                    e.message ?: "Failed to launch folder picker",
+                                    null
+                                )
+                            }
                         }
                         "safExists" -> {
                             val uriStr = call.argument<String>("uri") ?: ""
@@ -2216,7 +2365,8 @@ class MainActivity: FlutterFragmentActivity() {
                                 val dir = ensureDocumentDir(Uri.parse(treeUriStr), relativeDir) ?: return@withContext null
                                 val existing = dir.findFile(fileName)
                                 val createdNew = existing == null
-                                val doc = existing ?: dir.createFile(mimeType, fileName) ?: return@withContext null
+                                val doc = createOrReuseDocumentFile(dir, mimeType, fileName)
+                                    ?: return@withContext null
                                 if (!writeUriFromPath(doc.uri, srcPath)) {
                                     if (createdNew) {
                                         doc.delete()
@@ -2714,16 +2864,6 @@ class MainActivity: FlutterFragmentActivity() {
                             }
                             result.success(null)
                         }
-                        "searchDeezerAll" -> {
-                            val query = call.argument<String>("query") ?: ""
-                            val trackLimit = call.argument<Int>("track_limit") ?: 15
-                            val artistLimit = call.argument<Int>("artist_limit") ?: 2
-                            val filter = call.argument<String>("filter") ?: ""
-                            val response = withContext(Dispatchers.IO) {
-                                Gobackend.searchDeezerAll(query, trackLimit.toLong(), artistLimit.toLong(), filter)
-                            }
-                            result.success(response)
-                        }
                         "searchTidalAll" -> {
                             val query = call.argument<String>("query") ?: ""
                             val trackLimit = call.argument<Int>("track_limit") ?: 15
@@ -2965,6 +3105,13 @@ class MainActivity: FlutterFragmentActivity() {
                             }
                             result.success(response)
                         }
+                        "setDownloadFallbackExtensionIds" -> {
+                            val extensionIdsJson = call.argument<String>("extension_ids") ?: ""
+                            withContext(Dispatchers.IO) {
+                                Gobackend.setExtensionFallbackProviderIDsJSON(extensionIdsJson)
+                            }
+                            result.success(null)
+                        }
                         "setMetadataProviderPriority" -> {
                             val priorityJson = call.argument<String>("priority") ?: "[]"
                             withContext(Dispatchers.IO) {

android/gradle.properties

@@ -1,2 +1,2 @@
-org.gradle.jvmargs=-Xmx4G -XX:MaxMetaspaceSize=2G -XX:ReservedCodeCacheSize=256m -XX:+HeapDumpOnOutOfMemoryError
+org.gradle.jvmargs=-Xmx2g -XX:MaxMetaspaceSize=512m -XX:ReservedCodeCacheSize=256m -XX:+HeapDumpOnOutOfMemoryError
 android.useAndroidX=true

apps.json

@@ -7,12 +7,12 @@
       "name": "SpotiFLAC",
       "bundleIdentifier": "com.zarzet.spotiflac",
       "developerName": "zarzet",
-      "version": "3.9.0",
-      "versionDate": "2026-03-25",
-      "downloadURL": "https://github.com/zarzet/SpotiFLAC-Mobile/releases/download/v3.9.0/SpotiFLAC-v3.9.0-ios-unsigned.ipa",
+      "version": "4.3.1",
+      "versionDate": "2026-04-14",
+      "downloadURL": "https://github.com/zarzet/SpotiFLAC-Mobile/releases/download/v4.3.1/SpotiFLAC-v4.3.1-ios-unsigned.ipa",
       "localizedDescription": "Mobile version of SpotiFLAC written in Flutter. Download Tracks in true FLAC from Tidal, Qobuz, & Amazon Music.",
       "iconURL": "https://raw.githubusercontent.com/zarzet/SpotiFLAC-Mobile/main/assets/images/logo.png",
-      "size": 34477323
+      "size": 34773644
     }
   ]
 }

go_backend/ape_tags.go

@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"io"
 	"os"
-	"strconv"
 	"strings"
 )
 
@@ -367,12 +366,9 @@ func APETagToAudioMetadata(tag *APETag) *AudioMetadata {
 		case "DATE":
 			metadata.Date = value
 		case "TRACK", "TRACKNUMBER":
-			// APE track format can be "3" or "3/12"
-			trackNum, _ := strconv.Atoi(strings.Split(value, "/")[0])
-			metadata.TrackNumber = trackNum
+			metadata.TrackNumber, metadata.TotalTracks = parseIndexPair(value)
 		case "DISC", "DISCNUMBER":
-			discNum, _ := strconv.Atoi(strings.Split(value, "/")[0])
-			metadata.DiscNumber = discNum
+			metadata.DiscNumber, metadata.TotalDiscs = parseIndexPair(value)
 		case "ISRC":
 			metadata.ISRC = value
 		case "LYRICS", "UNSYNCEDLYRICS":
@@ -425,10 +421,10 @@ func AudioMetadataToAPEItems(metadata *AudioMetadata) []APETagItem {
 		addItem("Year", metadata.Year)
 	}
 	if metadata.TrackNumber > 0 {
-		addItem("Track", strconv.Itoa(metadata.TrackNumber))
+		addItem("Track", formatIndexValue(metadata.TrackNumber, metadata.TotalTracks))
 	}
 	if metadata.DiscNumber > 0 {
-		addItem("Disc", strconv.Itoa(metadata.DiscNumber))
+		addItem("Disc", formatIndexValue(metadata.DiscNumber, metadata.TotalDiscs))
 	}
 	addItem("ISRC", metadata.ISRC)
 	addItem("Lyrics", metadata.Lyrics)
@@ -453,7 +449,7 @@ func apeKeysFromFields(fields map[string]string) map[string]struct{} {
 		"artist":                "ARTIST",
 		"album":                 "ALBUM",
 		"album_artist":          "ALBUM ARTIST",
-		"date":                  "YEAR",
+		"date":                  "DATE",
 		"genre":                 "GENRE",
 		"track_number":          "TRACK",
 		"disc_number":           "DISC",
@@ -475,7 +471,7 @@ func apeKeysFromFields(fields map[string]string) map[string]struct{} {
 		}
 	}
 	// Some fields have reader aliases that must also be cleared when the
-	// canonical key is updated (e.g. "Year" writer ↔ DATE/YEAR reader,
+	// canonical key is updated (e.g. DATE writer ↔ DATE/YEAR reader,
 	// DISC ↔ DISCNUMBER, TRACK ↔ TRACKNUMBER, "ALBUM ARTIST" ↔ ALBUMARTIST,
 	// LABEL ↔ PUBLISHER, LYRICS ↔ UNSYNCEDLYRICS).
 	if _, present := fields["date"]; present {
@@ -484,9 +480,15 @@ func apeKeysFromFields(fields map[string]string) map[string]struct{} {
 	if _, present := fields["disc_number"]; present {
 		result["DISCNUMBER"] = struct{}{}
 	}
+	if _, present := fields["disc_total"]; present {
+		result["DISCNUMBER"] = struct{}{}
+	}
 	if _, present := fields["track_number"]; present {
 		result["TRACKNUMBER"] = struct{}{}
 	}
+	if _, present := fields["track_total"]; present {
+		result["TRACKNUMBER"] = struct{}{}
+	}
 	if _, present := fields["album_artist"]; present {
 		result["ALBUMARTIST"] = struct{}{}
 	}

go_backend/audio_metadata.go

@@ -21,7 +21,9 @@ type AudioMetadata struct {
 	Year        string
 	Date        string
 	TrackNumber int
+	TotalTracks int
 	DiscNumber  int
+	TotalDiscs  int
 	ISRC        string
 	Lyrics      string
 	Label       string
@@ -173,9 +175,9 @@ func parseID3v22Frames(data []byte, metadata *AudioMetadata, tagUnsync bool) {
 		case "TCO":
 			metadata.Genre = cleanGenre(value)
 		case "TRK":
-			metadata.TrackNumber = parseTrackNumber(value)
+			metadata.TrackNumber, metadata.TotalTracks = parseIndexPair(value)
 		case "TPA":
-			metadata.DiscNumber = parseTrackNumber(value)
+			metadata.DiscNumber, metadata.TotalDiscs = parseIndexPair(value)
 		case "TCM":
 			metadata.Composer = value
 		case "TPB":
@@ -292,9 +294,9 @@ func parseID3v23Frames(data []byte, metadata *AudioMetadata, version byte, tagUn
 		case "TCON":
 			metadata.Genre = cleanGenre(value)
 		case "TRCK":
-			metadata.TrackNumber = parseTrackNumber(value)
+			metadata.TrackNumber, metadata.TotalTracks = parseIndexPair(value)
 		case "TPOS":
-			metadata.DiscNumber = parseTrackNumber(value)
+			metadata.DiscNumber, metadata.TotalDiscs = parseIndexPair(value)
 		case "TSRC":
 			metadata.ISRC = value
 		case "TCOM":
@@ -580,14 +582,28 @@ func cleanGenre(genre string) string {
 }
 
 func parseTrackNumber(s string) int {
-	s = strings.TrimSpace(s)
-	if idx := strings.Index(s, "/"); idx > 0 {
-		s = s[:idx]
-	}
-	num, _ := strconv.Atoi(s)
+	num, _ := parseIndexPair(s)
 	return num
 }
 
+func parseIndexPair(s string) (int, int) {
+	s = strings.TrimSpace(s)
+	if s == "" {
+		return 0, 0
+	}
+
+	first := s
+	second := ""
+	if idx := strings.Index(s, "/"); idx > 0 {
+		first = s[:idx]
+		second = s[idx+1:]
+	}
+
+	num, _ := strconv.Atoi(strings.TrimSpace(first))
+	total, _ := strconv.Atoi(strings.TrimSpace(second))
+	return num, total
+}
+
 func removeUnsync(data []byte) []byte {
 	if len(data) == 0 {
 		return data
@@ -1037,9 +1053,9 @@ func parseVorbisComments(data []byte, metadata *AudioMetadata) {
 		case "GENRE":
 			metadata.Genre = value
 		case "TRACKNUMBER", "TRACK":
-			metadata.TrackNumber = parseTrackNumber(value)
+			metadata.TrackNumber, metadata.TotalTracks = parseIndexPair(value)
 		case "DISCNUMBER", "DISC":
-			metadata.DiscNumber = parseTrackNumber(value)
+			metadata.DiscNumber, metadata.TotalDiscs = parseIndexPair(value)
 		case "ISRC":
 			metadata.ISRC = value
 		case "COMPOSER":

go_backend/cancel.go

@@ -10,6 +10,7 @@ import (
 var ErrDownloadCancelled = errors.New("download cancelled")
 
 type cancelEntry struct {
+	ctx      context.Context
 	cancel   context.CancelFunc
 	canceled bool
 }
@@ -27,8 +28,21 @@ func initDownloadCancel(itemID string) context.Context {
 	cancelMu.Lock()
 	defer cancelMu.Unlock()
 
+	if entry, ok := cancelMap[itemID]; ok {
+		if entry.ctx == nil {
+			ctx, cancel := context.WithCancel(context.Background())
+			entry.ctx = ctx
+			entry.cancel = cancel
+			if entry.canceled && entry.cancel != nil {
+				entry.cancel()
+			}
+		}
+		return entry.ctx
+	}
+
 	ctx, cancel := context.WithCancel(context.Background())
 	cancelMap[itemID] = &cancelEntry{
+		ctx:      ctx,
 		cancel:   cancel,
 		canceled: false,
 	}

go_backend/cue_parser.go

@@ -513,6 +513,11 @@ func scanCueSheetForLibrary(cuePath string, sheet *CueSheet, audioPath, virtualP
 			album = "Unknown Album"
 		}
 
+		composer := track.Composer
+		if composer == "" {
+			composer = sheet.Composer
+		}
+
 		var duration int
 		if i+1 < len(sheet.Tracks) {
 			nextStart := sheet.Tracks[i+1].StartTime
@@ -539,12 +544,15 @@ func scanCueSheetForLibrary(cuePath string, sheet *CueSheet, audioPath, virtualP
 			ScannedAt:   scanTime,
 			ISRC:        track.ISRC,
 			TrackNumber: track.Number,
+			TotalTracks: len(sheet.Tracks),
 			DiscNumber:  1,
+			TotalDiscs:  1,
 			Duration:    duration,
 			ReleaseDate: sheet.Date,
 			BitDepth:    bitDepth,
 			SampleRate:  sampleRate,
 			Genre:       sheet.Genre,
+			Composer:    composer,
 			Format:      "cue+" + strings.TrimPrefix(audioExt, "."),
 		}
 

go_backend/deezer.go

@@ -630,6 +630,12 @@ func (c *DeezerClient) GetAlbum(ctx context.Context, albumID string) (*AlbumResp
 	}
 
 	isrcMap := c.fetchISRCsParallel(ctx, allTracks)
+	totalDiscs := 0
+	for _, track := range allTracks {
+		if track.DiskNumber > totalDiscs {
+			totalDiscs = track.DiskNumber
+		}
+	}
 
 	tracks := make([]AlbumTrackMetadata, 0, len(allTracks))
 	albumType := album.RecordType
@@ -658,6 +664,7 @@ func (c *DeezerClient) GetAlbum(ctx context.Context, albumID string) (*AlbumResp
 			TrackNumber: trackNum,
 			TotalTracks: album.NbTracks,
 			DiscNumber:  track.DiskNumber,
+			TotalDiscs:  totalDiscs,
 			ExternalURL: track.Link,
 			ISRC:        isrc,
 			AlbumID:     fmt.Sprintf("deezer:%d", album.ID),

go_backend/deezer_download.go

@@ -1,444 +0,0 @@
-package gobackend
-
-import (
-	"bufio"
-	"bytes"
-	"context"
-	"encoding/json"
-	"errors"
-	"fmt"
-	"io"
-	"net/http"
-	"os"
-	"path/filepath"
-	"strings"
-)
-
-const deezerMusicDLURL = "https://api.zarz.moe/v1/dzr"
-
-type DeezerDownloadResult struct {
-	FilePath    string
-	BitDepth    int
-	SampleRate  int
-	Title       string
-	Artist      string
-	Album       string
-	ReleaseDate string
-	TrackNumber int
-	DiscNumber  int
-	ISRC        string
-	LyricsLRC   string
-}
-
-func isLikelySpotifyTrackID(value string) bool {
-	if len(value) != 22 {
-		return false
-	}
-	for _, r := range value {
-		switch {
-		case r >= 'A' && r <= 'Z':
-		case r >= 'a' && r <= 'z':
-		case r >= '0' && r <= '9':
-		default:
-			return false
-		}
-	}
-	return true
-}
-
-func resolveDeezerTrackURL(req DownloadRequest) (string, error) {
-	deezerID := strings.TrimSpace(req.DeezerID)
-	if deezerID == "" {
-		if prefixed, found := strings.CutPrefix(strings.TrimSpace(req.SpotifyID), "deezer:"); found {
-			deezerID = strings.TrimSpace(prefixed)
-		}
-	}
-	if deezerID != "" {
-		trackURL := fmt.Sprintf("https://www.deezer.com/track/%s", deezerID)
-		if err := verifyDeezerTrack(req, deezerID, false); err != nil {
-			GoLog("[Deezer] Direct ID %s verification failed: %v\n", deezerID, err)
-			// Don't reject direct IDs from request payload — they're presumably correct.
-		}
-		return trackURL, nil
-	}
-
-	spotifyID := strings.TrimSpace(req.SpotifyID)
-	if spotifyID != "" && isLikelySpotifyTrackID(spotifyID) {
-		songlink := NewSongLinkClient()
-		availability, err := songlink.CheckTrackAvailability(spotifyID, "")
-		if err == nil && availability.Deezer && availability.DeezerURL != "" {
-			resolvedID := extractDeezerIDFromURL(availability.DeezerURL)
-			if resolvedID != "" {
-				if verifyErr := verifyDeezerTrack(req, resolvedID, true); verifyErr != nil {
-					GoLog("[Deezer] SongLink ID %s rejected: %v\n", resolvedID, verifyErr)
-					// Fall through to ISRC search instead of using wrong track.
-				} else {
-					return availability.DeezerURL, nil
-				}
-			} else {
-				return availability.DeezerURL, nil
-			}
-		}
-	}
-
-	isrc := strings.TrimSpace(req.ISRC)
-	if isrc != "" {
-		ctx, cancel := context.WithTimeout(context.Background(), SongLinkTimeout)
-		defer cancel()
-		track, err := GetDeezerClient().SearchByISRC(ctx, isrc)
-		if err == nil && track != nil {
-			resolvedID := songLinkExtractDeezerTrackID(track)
-			if resolvedID != "" {
-				if verifyErr := verifyDeezerTrack(req, resolvedID, false); verifyErr != nil {
-					GoLog("[Deezer] ISRC-resolved ID %s rejected: %v\n", resolvedID, verifyErr)
-					return "", fmt.Errorf("deezer track resolved via ISRC does not match: %w", verifyErr)
-				}
-				return fmt.Sprintf("https://www.deezer.com/track/%s", resolvedID), nil
-			}
-		}
-	}
-
-	return "", fmt.Errorf("could not resolve Deezer track URL")
-}
-
-func verifyDeezerTrack(req DownloadRequest, deezerID string, skipNameVerification bool) error {
-	ctx, cancel := context.WithTimeout(context.Background(), SongLinkTimeout)
-	defer cancel()
-	trackResp, err := GetDeezerClient().GetTrack(ctx, deezerID)
-	if err != nil {
-		return nil // Can't verify — don't block the download.
-	}
-	resolved := resolvedTrackInfo{
-		Title:                trackResp.Track.Name,
-		ArtistName:           trackResp.Track.Artists,
-		ISRC:                 trackResp.Track.ISRC,
-		Duration:             trackResp.Track.DurationMS / 1000,
-		SkipNameVerification: skipNameVerification,
-	}
-	if !trackMatchesRequest(req, resolved, "Deezer") {
-		return fmt.Errorf("expected '%s - %s', got '%s - %s'",
-			req.ArtistName, req.TrackName, resolved.ArtistName, resolved.Title)
-	}
-	GoLog("[Deezer] Track %s verified: '%s - %s' ✓\n", deezerID, resolved.ArtistName, resolved.Title)
-	return nil
-}
-
-type deezerMusicDLRequest struct {
-	Platform string `json:"platform"`
-	URL      string `json:"url"`
-}
-
-func (c *DeezerClient) GetMusicDLDownloadURL(deezerTrackURL string) (string, error) {
-	payload := deezerMusicDLRequest{
-		Platform: "deezer",
-		URL:      deezerTrackURL,
-	}
-	jsonData, err := json.Marshal(payload)
-	if err != nil {
-		return "", fmt.Errorf("failed to encode MusicDL request: %w", err)
-	}
-
-	req, err := http.NewRequest(http.MethodPost, deezerMusicDLURL, bytes.NewReader(jsonData))
-	if err != nil {
-		return "", fmt.Errorf("failed to create MusicDL request: %w", err)
-	}
-	req.Header.Set("Content-Type", "application/json")
-	req.Header.Set("User-Agent", getRandomUserAgent())
-
-	resp, err := c.httpClient.Do(req)
-	if err != nil {
-		return "", fmt.Errorf("MusicDL request failed: %w", err)
-	}
-	defer resp.Body.Close()
-
-	body, err := io.ReadAll(io.LimitReader(resp.Body, 64*1024))
-	if err != nil {
-		return "", fmt.Errorf("failed to read MusicDL response: %w", err)
-	}
-
-	if resp.StatusCode != http.StatusOK {
-		return "", fmt.Errorf("MusicDL returned HTTP %d: %s", resp.StatusCode, strings.TrimSpace(string(body)))
-	}
-
-	var raw map[string]any
-	if err := json.Unmarshal(body, &raw); err != nil {
-		return "", fmt.Errorf("invalid MusicDL JSON: %w", err)
-	}
-
-	if errMsg, ok := raw["error"].(string); ok && strings.TrimSpace(errMsg) != "" {
-		return "", fmt.Errorf("MusicDL error: %s", errMsg)
-	}
-
-	for _, key := range []string{"download_url", "url", "link"} {
-		if urlVal, ok := raw[key].(string); ok && strings.TrimSpace(urlVal) != "" {
-			return strings.TrimSpace(urlVal), nil
-		}
-	}
-	if data, ok := raw["data"].(map[string]any); ok {
-		for _, key := range []string{"download_url", "url", "link"} {
-			if urlVal, ok := data[key].(string); ok && strings.TrimSpace(urlVal) != "" {
-				return strings.TrimSpace(urlVal), nil
-			}
-		}
-	}
-
-	return "", fmt.Errorf("no download URL found in MusicDL response")
-}
-
-func (c *DeezerClient) DownloadFromMusicDL(deezerTrackURL, outputPath string, outputFD int, itemID string) error {
-	GoLog("[Deezer] Resolving download URL via MusicDL for: %s\n", deezerTrackURL)
-
-	downloadURL, err := c.GetMusicDLDownloadURL(deezerTrackURL)
-	if err != nil {
-		return err
-	}
-	GoLog("[Deezer] MusicDL returned download URL, starting download...\n")
-
-	ctx := context.Background()
-	if itemID != "" {
-		StartItemProgress(itemID)
-		defer CompleteItemProgress(itemID)
-		ctx = initDownloadCancel(itemID)
-		defer clearDownloadCancel(itemID)
-	}
-
-	if isDownloadCancelled(itemID) {
-		return ErrDownloadCancelled
-	}
-
-	req, err := http.NewRequestWithContext(ctx, "GET", downloadURL, nil)
-	if err != nil {
-		return fmt.Errorf("failed to create download request: %w", err)
-	}
-	req.Header.Set("User-Agent", getRandomUserAgent())
-
-	resp, err := GetDownloadClient().Do(req)
-	if err != nil {
-		if isDownloadCancelled(itemID) {
-			return ErrDownloadCancelled
-		}
-		return fmt.Errorf("download request failed: %w", err)
-	}
-	defer resp.Body.Close()
-
-	if resp.StatusCode != http.StatusOK {
-		return fmt.Errorf("download returned HTTP %d", resp.StatusCode)
-	}
-
-	expectedSize := resp.ContentLength
-	if expectedSize > 0 && itemID != "" {
-		SetItemBytesTotal(itemID, expectedSize)
-	}
-
-	out, err := openOutputForWrite(outputPath, outputFD)
-	if err != nil {
-		return err
-	}
-
-	bufWriter := bufio.NewWriterSize(out, 256*1024)
-	var written int64
-	if itemID != "" {
-		pw := NewItemProgressWriter(bufWriter, itemID)
-		written, err = io.Copy(pw, resp.Body)
-	} else {
-		written, err = io.Copy(bufWriter, resp.Body)
-	}
-
-	flushErr := bufWriter.Flush()
-	closeErr := out.Close()
-
-	if err != nil {
-		cleanupOutputOnError(outputPath, outputFD)
-		if isDownloadCancelled(itemID) {
-			return ErrDownloadCancelled
-		}
-		return fmt.Errorf("download interrupted: %w", err)
-	}
-	if flushErr != nil {
-		cleanupOutputOnError(outputPath, outputFD)
-		return fmt.Errorf("failed to flush output: %w", flushErr)
-	}
-	if closeErr != nil {
-		cleanupOutputOnError(outputPath, outputFD)
-		return fmt.Errorf("failed to close output: %w", closeErr)
-	}
-
-	if expectedSize > 0 && written != expectedSize {
-		cleanupOutputOnError(outputPath, outputFD)
-		return fmt.Errorf("incomplete download: expected %d bytes, got %d bytes", expectedSize, written)
-	}
-
-	GoLog("[Deezer] Downloaded via MusicDL: %.2f MB\n", float64(written)/(1024*1024))
-	return nil
-}
-
-func downloadFromDeezer(req DownloadRequest) (DeezerDownloadResult, error) {
-	deezerClient := GetDeezerClient()
-	isSafOutput := isFDOutput(req.OutputFD) || strings.TrimSpace(req.OutputPath) != ""
-
-	if !isSafOutput {
-		if existingFile, exists := checkISRCExistsInternal(req.OutputDir, req.ISRC); exists {
-			return DeezerDownloadResult{FilePath: "EXISTS:" + existingFile}, nil
-		}
-	}
-
-	filename := buildFilenameFromTemplate(req.FilenameFormat, map[string]interface{}{
-		"title":  req.TrackName,
-		"artist": req.ArtistName,
-		"album":  req.AlbumName,
-		"track":  req.TrackNumber,
-		"year":   extractYear(req.ReleaseDate),
-		"date":   req.ReleaseDate,
-		"disc":   req.DiscNumber,
-	})
-
-	var outputPath string
-	if isSafOutput {
-		outputPath = strings.TrimSpace(req.OutputPath)
-		if outputPath == "" && isFDOutput(req.OutputFD) {
-			outputPath = fmt.Sprintf("/proc/self/fd/%d", req.OutputFD)
-		}
-	} else {
-		filename = sanitizeFilename(filename) + ".flac"
-		outputPath = filepath.Join(req.OutputDir, filename)
-		if fileInfo, statErr := os.Stat(outputPath); statErr == nil && fileInfo.Size() > 0 {
-			return DeezerDownloadResult{FilePath: "EXISTS:" + outputPath}, nil
-		}
-	}
-
-	var parallelResult *ParallelDownloadResult
-	parallelDone := make(chan struct{})
-	go func() {
-		defer close(parallelDone)
-		coverURL := req.CoverURL
-		embedLyrics := req.EmbedLyrics
-		if !req.EmbedMetadata {
-			coverURL = ""
-			embedLyrics = false
-		}
-		parallelResult = FetchCoverAndLyricsParallel(
-			coverURL,
-			req.EmbedMaxQualityCover,
-			req.SpotifyID,
-			req.TrackName,
-			req.ArtistName,
-			embedLyrics,
-			int64(req.DurationMS),
-		)
-	}()
-
-	deezerTrackURL, deezerURLErr := resolveDeezerTrackURL(req)
-	if deezerURLErr != nil {
-		return DeezerDownloadResult{}, fmt.Errorf(
-			"deezer download failed: could not resolve Deezer URL: %w",
-			deezerURLErr,
-		)
-	}
-
-	GoLog("[Deezer] Trying MusicDL for: %s\n", deezerTrackURL)
-	downloadErr := deezerClient.DownloadFromMusicDL(
-		deezerTrackURL,
-		outputPath,
-		req.OutputFD,
-		req.ItemID,
-	)
-	if downloadErr != nil {
-		if errors.Is(downloadErr, ErrDownloadCancelled) {
-			return DeezerDownloadResult{}, ErrDownloadCancelled
-		}
-		return DeezerDownloadResult{}, fmt.Errorf(
-			"deezer download failed via MusicDL: %w",
-			downloadErr,
-		)
-	}
-
-	<-parallelDone
-
-	if req.ItemID != "" {
-		SetItemProgress(req.ItemID, 1.0, 0, 0)
-		SetItemFinalizing(req.ItemID)
-	}
-
-	metadata := Metadata{
-		Title:         req.TrackName,
-		Artist:        req.ArtistName,
-		Album:         req.AlbumName,
-		AlbumArtist:   req.AlbumArtist,
-		ArtistTagMode: req.ArtistTagMode,
-		Date:          req.ReleaseDate,
-		TrackNumber:   req.TrackNumber,
-		TotalTracks:   req.TotalTracks,
-		DiscNumber:    req.DiscNumber,
-		ISRC:          req.ISRC,
-		Genre:         req.Genre,
-		Label:         req.Label,
-		Copyright:     req.Copyright,
-	}
-
-	var coverData []byte
-	if parallelResult != nil && parallelResult.CoverData != nil {
-		coverData = parallelResult.CoverData
-	}
-
-	if isSafOutput || !req.EmbedMetadata {
-		if !req.EmbedMetadata {
-			GoLog("[Deezer] Metadata embedding disabled by settings, skipping in-backend metadata/lyrics embedding\n")
-		} else {
-			GoLog("[Deezer] SAF output detected - skipping in-backend metadata/lyrics embedding (handled in Flutter)\n")
-		}
-	} else {
-		if err := EmbedMetadataWithCoverData(outputPath, metadata, coverData); err != nil {
-			GoLog("[Deezer] Warning: failed to embed metadata: %v\n", err)
-		}
-
-		if req.EmbedLyrics && parallelResult != nil && parallelResult.LyricsLRC != "" {
-			lyricsMode := req.LyricsMode
-			if lyricsMode == "" {
-				lyricsMode = "embed"
-			}
-
-			if lyricsMode == "external" || lyricsMode == "both" {
-				if lrcPath, lrcErr := SaveLRCFile(outputPath, parallelResult.LyricsLRC); lrcErr != nil {
-					GoLog("[Deezer] Warning: failed to save LRC file: %v\n", lrcErr)
-				} else {
-					GoLog("[Deezer] LRC file saved: %s\n", lrcPath)
-				}
-			}
-
-			if lyricsMode == "embed" || lyricsMode == "both" {
-				if embedErr := EmbedLyrics(outputPath, parallelResult.LyricsLRC); embedErr != nil {
-					GoLog("[Deezer] Warning: failed to embed lyrics: %v\n", embedErr)
-				}
-			}
-		}
-	}
-
-	if !isSafOutput {
-		AddToISRCIndex(req.OutputDir, req.ISRC, outputPath)
-	}
-
-	bitDepth, sampleRate := 0, 0
-	if quality, qErr := GetAudioQuality(outputPath); qErr == nil {
-		bitDepth = quality.BitDepth
-		sampleRate = quality.SampleRate
-	}
-
-	lyricsLRC := ""
-	if req.EmbedMetadata && req.EmbedLyrics && parallelResult != nil && parallelResult.LyricsLRC != "" {
-		lyricsLRC = parallelResult.LyricsLRC
-	}
-
-	return DeezerDownloadResult{
-		FilePath:    outputPath,
-		BitDepth:    bitDepth,
-		SampleRate:  sampleRate,
-		Title:       req.TrackName,
-		Artist:      req.ArtistName,
-		Album:       req.AlbumName,
-		ReleaseDate: req.ReleaseDate,
-		TrackNumber: req.TrackNumber,
-		DiscNumber:  req.DiscNumber,
-		ISRC:        req.ISRC,
-		LyricsLRC:   lyricsLRC,
-	}, nil
-}

go_backend/exports_test.go

@@ -1,6 +1,24 @@
 package gobackend
 
-import "testing"
+import (
+	"context"
+	"testing"
+)
+
+func TestSetExtensionFallbackProviderIDsJSONEmptyStringResetsDefault(t *testing.T) {
+	original := GetExtensionFallbackProviderIDs()
+	defer SetExtensionFallbackProviderIDs(original)
+
+	SetExtensionFallbackProviderIDs([]string{"custom-ext"})
+
+	if err := SetExtensionFallbackProviderIDsJSON(""); err != nil {
+		t.Fatalf("SetExtensionFallbackProviderIDsJSON returned error: %v", err)
+	}
+
+	if got := GetExtensionFallbackProviderIDs(); got != nil {
+		t.Fatalf("expected nil fallback provider list after reset, got %v", got)
+	}
+}
 
 func TestBuildDownloadSuccessResponsePrefersRequestedAlbumMetadata(t *testing.T) {
 	req := DownloadRequest{
@@ -114,6 +132,124 @@ func TestBuildDownloadSuccessResponsePrefersProviderCoverURL(t *testing.T) {
 	}
 }
 
+func TestBuildDownloadSuccessResponseNormalizesDecryptionDescriptor(t *testing.T) {
+	req := DownloadRequest{
+		TrackName:  "Track",
+		ArtistName: "Artist",
+	}
+
+	result := DownloadResult{
+		Title:         "Track",
+		Artist:        "Artist",
+		DecryptionKey: "00112233",
+	}
+
+	resp := buildDownloadSuccessResponse(
+		req,
+		result,
+		"amazon",
+		"ok",
+		"/tmp/test.m4a",
+		false,
+	)
+
+	if resp.Decryption == nil {
+		t.Fatal("expected decryption descriptor to be present")
+	}
+	if resp.Decryption.Strategy != genericFFmpegMOVDecryptionStrategy {
+		t.Fatalf("strategy = %q", resp.Decryption.Strategy)
+	}
+	if resp.Decryption.Key != result.DecryptionKey {
+		t.Fatalf("key = %q, want %q", resp.Decryption.Key, result.DecryptionKey)
+	}
+}
+
+func TestFormatMusicBrainzGenrePrefersHighestCountTag(t *testing.T) {
+	got := formatMusicBrainzGenre([]musicBrainzTag{
+		{Name: "art pop", Count: 3},
+		{Name: "pop", Count: 8},
+		{Name: "dance pop", Count: 5},
+	})
+
+	if got != "Pop" {
+		t.Fatalf("genre = %q, want %q", got, "Pop")
+	}
+}
+
+func TestEnrichExtraMetadataByISRCFallsBackToMusicBrainzGenre(t *testing.T) {
+	origDeezerFetcher := fetchDeezerExtendedMetadataByISRC
+	origMusicBrainzFetcher := fetchMusicBrainzGenreByISRC
+	defer func() {
+		fetchDeezerExtendedMetadataByISRC = origDeezerFetcher
+		fetchMusicBrainzGenreByISRC = origMusicBrainzFetcher
+	}()
+
+	fetchDeezerExtendedMetadataByISRC = func(ctx context.Context, isrc string) (*AlbumExtendedMetadata, error) {
+		return nil, nil
+	}
+	fetchMusicBrainzGenreByISRC = func(isrc string) (string, error) {
+		if isrc != "TEST123" {
+			t.Fatalf("unexpected isrc: %q", isrc)
+		}
+		return "Alternative Rock", nil
+	}
+
+	genre := ""
+	label := ""
+	copyright := ""
+	enrichExtraMetadataByISRC("DownloadWithFallback", "TEST123", &genre, &label, &copyright)
+
+	if genre != "Alternative Rock" {
+		t.Fatalf("genre = %q, want fallback genre", genre)
+	}
+	if label != "" {
+		t.Fatalf("label = %q, want empty", label)
+	}
+	if copyright != "" {
+		t.Fatalf("copyright = %q, want empty", copyright)
+	}
+}
+
+func TestEnrichExtraMetadataByISRCPrefersDeezerGenre(t *testing.T) {
+	origDeezerFetcher := fetchDeezerExtendedMetadataByISRC
+	origMusicBrainzFetcher := fetchMusicBrainzGenreByISRC
+	defer func() {
+		fetchDeezerExtendedMetadataByISRC = origDeezerFetcher
+		fetchMusicBrainzGenreByISRC = origMusicBrainzFetcher
+	}()
+
+	musicBrainzCalled := false
+	fetchDeezerExtendedMetadataByISRC = func(ctx context.Context, isrc string) (*AlbumExtendedMetadata, error) {
+		return &AlbumExtendedMetadata{
+			Genre:     "Synthpop",
+			Label:     "EMI",
+			Copyright: "(C) Test",
+		}, nil
+	}
+	fetchMusicBrainzGenreByISRC = func(isrc string) (string, error) {
+		musicBrainzCalled = true
+		return "Rock", nil
+	}
+
+	genre := ""
+	label := ""
+	copyright := ""
+	enrichExtraMetadataByISRC("DownloadWithFallback", "TEST456", &genre, &label, &copyright)
+
+	if genre != "Synthpop" {
+		t.Fatalf("genre = %q, want Deezer genre", genre)
+	}
+	if label != "EMI" {
+		t.Fatalf("label = %q, want Deezer label", label)
+	}
+	if copyright != "(C) Test" {
+		t.Fatalf("copyright = %q, want Deezer copyright", copyright)
+	}
+	if musicBrainzCalled {
+		t.Fatal("expected MusicBrainz not to be called when Deezer already provides genre")
+	}
+}
+
 func TestApplyReEnrichTrackMetadataPreservesExistingReleaseDateWhenCandidateMissing(t *testing.T) {
 	req := reEnrichRequest{
 		SpotifyID:   "spotify-track-id",
@@ -195,13 +331,11 @@ func TestBuildReEnrichFFmpegMetadataOmitsEmptyFields(t *testing.T) {
 
 	metadata := buildReEnrichFFmpegMetadata(&req, "")
 
-	// Title and Artist are never written by re-enrich (they are search keys
-	// preserved as-is from the file).
-	if _, exists := metadata["TITLE"]; exists {
-		t.Fatalf("TITLE should not be in metadata: %#v", metadata)
+	if metadata["TITLE"] != "Song" {
+		t.Fatalf("title = %q", metadata["TITLE"])
 	}
-	if _, exists := metadata["ARTIST"]; exists {
-		t.Fatalf("ARTIST should not be in metadata: %#v", metadata)
+	if metadata["ARTIST"] != "Artist" {
+		t.Fatalf("artist = %q", metadata["ARTIST"])
 	}
 	if metadata["ALBUM"] != "Album" {
 		t.Fatalf("album = %q", metadata["ALBUM"])
@@ -224,3 +358,75 @@ func TestBuildReEnrichFFmpegMetadataOmitsEmptyFields(t *testing.T) {
 		}
 	}
 }
+
+func TestBuildReEnrichSearchQuerySkipsPlaceholderArtist(t *testing.T) {
+	req := reEnrichRequest{
+		TrackName:  "Sign of the Times",
+		ArtistName: "Unknown Artist",
+		AlbumName:  "Harry Styles",
+	}
+
+	query := buildReEnrichSearchQuery(req)
+	if query != "Sign of the Times" {
+		t.Fatalf("query = %q", query)
+	}
+
+	req = reEnrichRequest{
+		TrackName:  "Unknown Title",
+		ArtistName: "Unknown Artist",
+		AlbumName:  "Harry Styles",
+	}
+	query = buildReEnrichSearchQuery(req)
+	if query != "Harry Styles" {
+		t.Fatalf("fallback album query = %q", query)
+	}
+}
+
+func TestApplyReEnrichTrackMetadataCopiesComposerAndTotals(t *testing.T) {
+	req := reEnrichRequest{}
+
+	applyReEnrichTrackMetadata(&req, ExtTrackMetadata{
+		Name:        "Resolved Song",
+		Artists:     "Resolved Artist",
+		TrackNumber: 7,
+		TotalTracks: 12,
+		DiscNumber:  2,
+		TotalDiscs:  3,
+		Composer:    "Composer",
+	})
+
+	if req.TrackNumber != 7 || req.TotalTracks != 12 {
+		t.Fatalf("track metadata = %d/%d", req.TrackNumber, req.TotalTracks)
+	}
+	if req.DiscNumber != 2 || req.TotalDiscs != 3 {
+		t.Fatalf("disc metadata = %d/%d", req.DiscNumber, req.TotalDiscs)
+	}
+	if req.TrackName != "Resolved Song" || req.ArtistName != "Resolved Artist" {
+		t.Fatalf("basic tags = %q / %q", req.TrackName, req.ArtistName)
+	}
+	if req.Composer != "Composer" {
+		t.Fatalf("composer = %q", req.Composer)
+	}
+}
+
+func TestBuildReEnrichFFmpegMetadataFormatsTotalsAndComposer(t *testing.T) {
+	req := reEnrichRequest{
+		TrackNumber: 7,
+		TotalTracks: 12,
+		DiscNumber:  2,
+		TotalDiscs:  3,
+		Composer:    "Composer",
+	}
+
+	metadata := buildReEnrichFFmpegMetadata(&req, "")
+
+	if metadata["TRACKNUMBER"] != "7/12" {
+		t.Fatalf("TRACKNUMBER = %q", metadata["TRACKNUMBER"])
+	}
+	if metadata["DISCNUMBER"] != "2/3" {
+		t.Fatalf("DISCNUMBER = %q", metadata["DISCNUMBER"])
+	}
+	if metadata["COMPOSER"] != "Composer" {
+		t.Fatalf("COMPOSER = %q", metadata["COMPOSER"])
+	}
+}

go_backend/extension_manager.go

@@ -43,12 +43,12 @@ func compareVersions(v1, v2 string) int {
 	return 0
 }
 
-type LoadedExtension struct {
+type loadedExtension struct {
 	ID          string             `json:"id"`
 	Manifest    *ExtensionManifest `json:"manifest"`
 	VM          *goja.Runtime      `json:"-"`
 	VMMu        sync.Mutex         `json:"-"`
-	runtime     *ExtensionRuntime
+	runtime     *extensionRuntime
 	initialized bool
 	Enabled     bool   `json:"enabled"`
 	Error       string `json:"error,omitempty"`
@@ -73,7 +73,7 @@ func getExtensionInitSettings(extensionID string) map[string]interface{} {
 	return filtered
 }
 
-func ensureRuntimeReadyLocked(ext *LoadedExtension, applyStoredSettings bool) error {
+func ensureRuntimeReadyLocked(ext *loadedExtension, applyStoredSettings bool) error {
 	if ext.VM == nil || ext.runtime == nil {
 		if err := initializeVMLocked(ext); err != nil {
 			ext.Error = err.Error()
@@ -100,14 +100,14 @@ func ensureRuntimeReadyLocked(ext *LoadedExtension, applyStoredSettings bool) er
 	return nil
 }
 
-func (ext *LoadedExtension) ensureRuntimeReady() error {
+func (ext *loadedExtension) ensureRuntimeReady() error {
 	ext.VMMu.Lock()
 	defer ext.VMMu.Unlock()
 
 	return ensureRuntimeReadyLocked(ext, true)
 }
 
-func (ext *LoadedExtension) lockReadyVM() (*goja.Runtime, error) {
+func (ext *loadedExtension) lockReadyVM() (*goja.Runtime, error) {
 	ext.VMMu.Lock()
 	if err := ensureRuntimeReadyLocked(ext, true); err != nil {
 		ext.VMMu.Unlock()
@@ -116,28 +116,28 @@ func (ext *LoadedExtension) lockReadyVM() (*goja.Runtime, error) {
 	return ext.VM, nil
 }
 
-type ExtensionManager struct {
+type extensionManager struct {
 	mu            sync.RWMutex
-	extensions    map[string]*LoadedExtension
+	extensions    map[string]*loadedExtension
 	extensionsDir string
 	dataDir       string
 }
 
 var (
-	globalExtManager     *ExtensionManager
+	globalExtManager     *extensionManager
 	globalExtManagerOnce sync.Once
 )
 
-func GetExtensionManager() *ExtensionManager {
+func getExtensionManager() *extensionManager {
 	globalExtManagerOnce.Do(func() {
-		globalExtManager = &ExtensionManager{
-			extensions: make(map[string]*LoadedExtension),
+		globalExtManager = &extensionManager{
+			extensions: make(map[string]*loadedExtension),
 		}
 	})
 	return globalExtManager
 }
 
-func (m *ExtensionManager) SetDirectories(extensionsDir, dataDir string) error {
+func (m *extensionManager) SetDirectories(extensionsDir, dataDir string) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
@@ -154,7 +154,7 @@ func (m *ExtensionManager) SetDirectories(extensionsDir, dataDir string) error {
 	return nil
 }
 
-func (m *ExtensionManager) LoadExtensionFromFile(filePath string) (*LoadedExtension, error) {
+func (m *extensionManager) LoadExtensionFromFile(filePath string) (*loadedExtension, error) {
 	if !strings.HasSuffix(strings.ToLower(filePath), ".spotiflac-ext") {
 		return nil, fmt.Errorf("Invalid file format. Please select a .spotiflac-ext file")
 	}
@@ -272,7 +272,7 @@ func (m *ExtensionManager) LoadExtensionFromFile(filePath string) (*LoadedExtens
 		return nil, fmt.Errorf("failed to create extension data directory: %w", err)
 	}
 
-	ext := &LoadedExtension{
+	ext := &loadedExtension{
 		ID:        manifest.Name,
 		Manifest:  manifest,
 		Enabled:   false, // New extensions start disabled
@@ -292,7 +292,7 @@ func (m *ExtensionManager) LoadExtensionFromFile(filePath string) (*LoadedExtens
 	return ext, nil
 }
 
-func initializeVMLocked(ext *LoadedExtension) error {
+func initializeVMLocked(ext *loadedExtension) error {
 	ext.VM = nil
 	ext.runtime = nil
 	ext.initialized = false
@@ -305,7 +305,7 @@ func initializeVMLocked(ext *LoadedExtension) error {
 		return fmt.Errorf("failed to read index.js: %w", err)
 	}
 
-	runtime := NewExtensionRuntime(ext)
+	runtime := newExtensionRuntime(ext)
 	ext.runtime = runtime
 	runtime.RegisterAPIs(vm)
 	runtime.RegisterGoBackendAPIs(vm)
@@ -342,14 +342,14 @@ func initializeVMLocked(ext *LoadedExtension) error {
 	return nil
 }
 
-func (m *ExtensionManager) initializeVM(ext *LoadedExtension) error {
+func (m *extensionManager) initializeVM(ext *loadedExtension) error {
 	ext.VMMu.Lock()
 	defer ext.VMMu.Unlock()
 	return initializeVMLocked(ext)
 }
 
 func initializeExtensionWithSettingsLocked(
-	ext *LoadedExtension,
+	ext *loadedExtension,
 	settings map[string]interface{},
 ) error {
 	if ext.VM == nil {
@@ -405,7 +405,7 @@ func initializeExtensionWithSettingsLocked(
 	return nil
 }
 
-func runCleanupLocked(ext *LoadedExtension) error {
+func runCleanupLocked(ext *loadedExtension) error {
 	if ext.VM != nil {
 		script := `
 			(function() {
@@ -446,7 +446,7 @@ func runCleanupLocked(ext *LoadedExtension) error {
 	return nil
 }
 
-func teardownVMLocked(ext *LoadedExtension) {
+func teardownVMLocked(ext *loadedExtension) {
 	if err := runCleanupLocked(ext); err != nil {
 		GoLog("[Extension] Error calling cleanup for %s: %v\n", ext.ID, err)
 	}
@@ -461,7 +461,7 @@ func teardownVMLocked(ext *LoadedExtension) {
 	ext.initialized = false
 }
 
-func validateExtensionLoad(ext *LoadedExtension) error {
+func validateExtensionLoad(ext *loadedExtension) error {
 	ext.VMMu.Lock()
 	defer ext.VMMu.Unlock()
 
@@ -472,7 +472,7 @@ func validateExtensionLoad(ext *LoadedExtension) error {
 	return nil
 }
 
-func (m *ExtensionManager) UnloadExtension(extensionID string) error {
+func (m *extensionManager) UnloadExtension(extensionID string) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
@@ -491,7 +491,7 @@ func (m *ExtensionManager) UnloadExtension(extensionID string) error {
 	return nil
 }
 
-func (m *ExtensionManager) GetExtension(extensionID string) (*LoadedExtension, error) {
+func (m *extensionManager) GetExtension(extensionID string) (*loadedExtension, error) {
 	m.mu.RLock()
 	defer m.mu.RUnlock()
 
@@ -502,18 +502,18 @@ func (m *ExtensionManager) GetExtension(extensionID string) (*LoadedExtension, e
 	return ext, nil
 }
 
-func (m *ExtensionManager) GetAllExtensions() []*LoadedExtension {
+func (m *extensionManager) GetAllExtensions() []*loadedExtension {
 	m.mu.RLock()
 	defer m.mu.RUnlock()
 
-	result := make([]*LoadedExtension, 0, len(m.extensions))
+	result := make([]*loadedExtension, 0, len(m.extensions))
 	for _, ext := range m.extensions {
 		result = append(result, ext)
 	}
 	return result
 }
 
-func (m *ExtensionManager) SetExtensionEnabled(extensionID string, enabled bool) error {
+func (m *extensionManager) SetExtensionEnabled(extensionID string, enabled bool) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
@@ -547,7 +547,7 @@ func (m *ExtensionManager) SetExtensionEnabled(extensionID string, enabled bool)
 	return nil
 }
 
-func (m *ExtensionManager) LoadExtensionsFromDirectory(dirPath string) ([]string, []error) {
+func (m *extensionManager) LoadExtensionsFromDirectory(dirPath string) ([]string, []error) {
 	var loaded []string
 	var errors []error
 
@@ -585,7 +585,7 @@ func (m *ExtensionManager) LoadExtensionsFromDirectory(dirPath string) ([]string
 	return loaded, errors
 }
 
-func (m *ExtensionManager) loadExtensionFromDirectory(dirPath string) (*LoadedExtension, error) {
+func (m *extensionManager) loadExtensionFromDirectory(dirPath string) (*loadedExtension, error) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
@@ -615,7 +615,7 @@ func (m *ExtensionManager) loadExtensionFromDirectory(dirPath string) (*LoadedEx
 		return nil, fmt.Errorf("failed to create extension data directory: %w", err)
 	}
 
-	ext := &LoadedExtension{
+	ext := &loadedExtension{
 		ID:        manifest.Name,
 		Manifest:  manifest,
 		Enabled:   false, // Will be restored from settings store
@@ -643,7 +643,7 @@ func (m *ExtensionManager) loadExtensionFromDirectory(dirPath string) (*LoadedEx
 	return ext, nil
 }
 
-func (m *ExtensionManager) RemoveExtension(extensionID string) error {
+func (m *extensionManager) RemoveExtension(extensionID string) error {
 	ext, err := m.GetExtension(extensionID)
 	if err != nil {
 		return err
@@ -663,7 +663,7 @@ func (m *ExtensionManager) RemoveExtension(extensionID string) error {
 }
 
 // Only allows upgrades (new version > current version), not downgrades
-func (m *ExtensionManager) UpgradeExtension(filePath string) (*LoadedExtension, error) {
+func (m *extensionManager) UpgradeExtension(filePath string) (*loadedExtension, error) {
 	if !strings.HasSuffix(strings.ToLower(filePath), ".spotiflac-ext") {
 		return nil, fmt.Errorf("Invalid file format. Please select a .spotiflac-ext file")
 	}
@@ -777,7 +777,7 @@ func (m *ExtensionManager) UpgradeExtension(filePath string) (*LoadedExtension,
 		}
 	}
 
-	ext := &LoadedExtension{
+	ext := &loadedExtension{
 		ID:        newManifest.Name,
 		Manifest:  newManifest,
 		Enabled:   wasEnabled, // Preserve enabled state from before upgrade
@@ -812,7 +812,7 @@ type ExtensionUpgradeInfo struct {
 	IsInstalled    bool   `json:"is_installed"`
 }
 
-func (m *ExtensionManager) checkExtensionUpgradeInternal(filePath string) (*ExtensionUpgradeInfo, error) {
+func (m *extensionManager) checkExtensionUpgradeInternal(filePath string) (*ExtensionUpgradeInfo, error) {
 	if !strings.HasSuffix(strings.ToLower(filePath), ".spotiflac-ext") {
 		return nil, fmt.Errorf("Invalid file format. Please select a .spotiflac-ext file")
 	}
@@ -871,7 +871,7 @@ func (m *ExtensionManager) checkExtensionUpgradeInternal(filePath string) (*Exte
 	return info, nil
 }
 
-func (m *ExtensionManager) CheckExtensionUpgradeJSON(filePath string) (string, error) {
+func (m *extensionManager) CheckExtensionUpgradeJSON(filePath string) (string, error) {
 	info, err := m.checkExtensionUpgradeInternal(filePath)
 	if err != nil {
 		return "", err
@@ -885,7 +885,7 @@ func (m *ExtensionManager) CheckExtensionUpgradeJSON(filePath string) (string, e
 	return string(jsonBytes), nil
 }
 
-func (m *ExtensionManager) GetInstalledExtensionsJSON() (string, error) {
+func (m *extensionManager) GetInstalledExtensionsJSON() (string, error) {
 	extensions := m.GetAllExtensions()
 
 	type ExtensionInfo struct {
@@ -893,7 +893,6 @@ func (m *ExtensionManager) GetInstalledExtensionsJSON() (string, error) {
 		Name                   string                 `json:"name"`
 		DisplayName            string                 `json:"display_name"`
 		Version                string                 `json:"version"`
-		Author                 string                 `json:"author"`
 		Description            string                 `json:"description"`
 		Homepage               string                 `json:"homepage,omitempty"`
 		IconPath               string                 `json:"icon_path,omitempty"`
@@ -951,7 +950,6 @@ func (m *ExtensionManager) GetInstalledExtensionsJSON() (string, error) {
 			Name:                   ext.Manifest.Name,
 			DisplayName:            ext.Manifest.DisplayName,
 			Version:                ext.Manifest.Version,
-			Author:                 ext.Manifest.Author,
 			Description:            ext.Manifest.Description,
 			Homepage:               ext.Manifest.Homepage,
 			IconPath:               iconPath,
@@ -982,7 +980,7 @@ func (m *ExtensionManager) GetInstalledExtensionsJSON() (string, error) {
 	return string(jsonBytes), nil
 }
 
-func (m *ExtensionManager) InitializeExtension(extensionID string, settings map[string]interface{}) error {
+func (m *extensionManager) InitializeExtension(extensionID string, settings map[string]interface{}) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
@@ -1000,7 +998,7 @@ func (m *ExtensionManager) InitializeExtension(extensionID string, settings map[
 	return initializeExtensionWithSettingsLocked(ext, settings)
 }
 
-func (m *ExtensionManager) CleanupExtension(extensionID string) error {
+func (m *extensionManager) CleanupExtension(extensionID string) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
@@ -1022,7 +1020,7 @@ func (m *ExtensionManager) CleanupExtension(extensionID string) error {
 	return nil
 }
 
-func (m *ExtensionManager) UnloadAllExtensions() {
+func (m *extensionManager) UnloadAllExtensions() {
 	m.mu.Lock()
 	extensionIDs := make([]string, 0, len(m.extensions))
 	for id := range m.extensions {
@@ -1037,7 +1035,7 @@ func (m *ExtensionManager) UnloadAllExtensions() {
 	GoLog("[Extension] All extensions unloaded\n")
 }
 
-func (m *ExtensionManager) InvokeAction(extensionID string, actionName string) (map[string]interface{}, error) {
+func (m *extensionManager) InvokeAction(extensionID string, actionName string) (map[string]interface{}, error) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
@@ -1055,15 +1053,29 @@ func (m *ExtensionManager) InvokeAction(extensionID string, actionName string) (
 	}
 	defer ext.VMMu.Unlock()
 
+	// Merge extension return values onto the top-level JSON object so Flutter can read
+	// message, open_auth_url, setting_updates without unwrapping a nested "result" key.
 	script := fmt.Sprintf(`
 		(function() {
 			if (typeof extension !== 'undefined' && typeof extension.%s === 'function') {
 				try {
 					var result = extension.%s();
 					if (result && typeof result.then === 'function') {
-						// Handle promise - return pending status
 						return { success: true, pending: true, message: 'Action started' };
 					}
+					if (result !== null && result !== undefined && typeof result === 'object') {
+						var isArr = false;
+						if (typeof Array !== 'undefined' && Array.isArray) {
+							isArr = Array.isArray(result);
+						}
+						if (!isArr) {
+							var out = { success: true };
+							for (var k in result) {
+								out[k] = result[k];
+							}
+							return out;
+						}
+					}
 					return { success: true, result: result };
 				} catch (e) {
 					return { success: false, error: e.toString() };

go_backend/extension_manifest.go

@@ -105,7 +105,6 @@ type ExtensionManifest struct {
 	Name                   string                 `json:"name"`
 	DisplayName            string                 `json:"displayName"`
 	Version                string                 `json:"version"`
-	Author                 string                 `json:"author"`
 	Description            string                 `json:"description"`
 	Homepage               string                 `json:"homepage,omitempty"`
 	Icon                   string                 `json:"icon,omitempty"`
@@ -155,10 +154,6 @@ func (m *ExtensionManifest) Validate() error {
 		return &ManifestValidationError{Field: "version", Message: "version is required"}
 	}
 
-	if strings.TrimSpace(m.Author) == "" {
-		return &ManifestValidationError{Field: "author", Message: "author is required"}
-	}
-
 	if strings.TrimSpace(m.Description) == "" {
 		return &ManifestValidationError{Field: "description", Message: "description is required"}
 	}

go_backend/extension_providers_test.go

@@ -1,6 +1,10 @@
 package gobackend
 
-import "testing"
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
 
 func TestSetMetadataProviderPriorityAddsBuiltIns(t *testing.T) {
 	original := GetMetadataProviderPriority()
@@ -8,7 +12,7 @@ func TestSetMetadataProviderPriorityAddsBuiltIns(t *testing.T) {
 
 	SetMetadataProviderPriority([]string{"tidal"})
 	got := GetMetadataProviderPriority()
-	want := []string{"tidal", "deezer", "qobuz"}
+	want := []string{"tidal", "qobuz"}
 	if len(got) != len(want) {
 		t.Fatalf("unexpected priority length: got %v want %v", got, want)
 	}
@@ -19,6 +23,190 @@ func TestSetMetadataProviderPriorityAddsBuiltIns(t *testing.T) {
 	}
 }
 
+func TestSetExtensionFallbackProviderIDsSkipsBuiltInsAndDuplicates(t *testing.T) {
+	original := GetExtensionFallbackProviderIDs()
+	defer SetExtensionFallbackProviderIDs(original)
+
+	SetExtensionFallbackProviderIDs([]string{"ext-a", "tidal", "ext-a", " ext-b "})
+
+	got := GetExtensionFallbackProviderIDs()
+	want := []string{"ext-a", "ext-b"}
+	if len(got) != len(want) {
+		t.Fatalf("unexpected fallback provider length: got %v want %v", got, want)
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Fatalf("unexpected fallback provider at %d: got %v want %v", i, got, want)
+		}
+	}
+}
+
+func TestIsExtensionFallbackAllowedDefaultsToAllExtensions(t *testing.T) {
+	original := GetExtensionFallbackProviderIDs()
+	defer SetExtensionFallbackProviderIDs(original)
+
+	SetExtensionFallbackProviderIDs(nil)
+
+	if !isExtensionFallbackAllowed("custom-ext") {
+		t.Fatal("expected custom extension to be allowed when no fallback allowlist is configured")
+	}
+	if !isExtensionFallbackAllowed("qobuz") {
+		t.Fatal("expected built-in provider to remain allowed")
+	}
+}
+
+func TestIsExtensionFallbackAllowedRespectsAllowlist(t *testing.T) {
+	original := GetExtensionFallbackProviderIDs()
+	defer SetExtensionFallbackProviderIDs(original)
+
+	SetExtensionFallbackProviderIDs([]string{"allowed-ext"})
+
+	if !isExtensionFallbackAllowed("allowed-ext") {
+		t.Fatal("expected explicitly allowed extension to be permitted")
+	}
+	if isExtensionFallbackAllowed("blocked-ext") {
+		t.Fatal("expected extension outside allowlist to be blocked")
+	}
+	if isExtensionFallbackAllowed("deezer") {
+		t.Fatal("expected retired Deezer downloader to respect extension fallback allowlist")
+	}
+}
+
+func TestSetProviderPriorityRemovesRetiredDeezerDownloader(t *testing.T) {
+	original := GetProviderPriority()
+	defer SetProviderPriority(original)
+
+	SetProviderPriority([]string{"deezer", "qobuz", "custom-ext"})
+
+	got := GetProviderPriority()
+	want := []string{"qobuz", "custom-ext", "tidal"}
+	if len(got) != len(want) {
+		t.Fatalf("unexpected priority length: got %v want %v", got, want)
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Fatalf("unexpected priority at %d: got %v want %v", i, got, want)
+		}
+	}
+}
+
+func TestNormalizeDownloadDecryptionInfoPromotesLegacyKey(t *testing.T) {
+	normalized := normalizeDownloadDecryptionInfo(nil, " 001122 ")
+	if normalized == nil {
+		t.Fatal("expected legacy decryption key to produce normalized descriptor")
+	}
+	if normalized.Strategy != genericFFmpegMOVDecryptionStrategy {
+		t.Fatalf("strategy = %q", normalized.Strategy)
+	}
+	if normalized.Key != "001122" {
+		t.Fatalf("key = %q", normalized.Key)
+	}
+	if normalized.InputFormat != "mov" {
+		t.Fatalf("input format = %q", normalized.InputFormat)
+	}
+}
+
+func TestNormalizeDownloadDecryptionInfoCanonicalizesMovAliases(t *testing.T) {
+	normalized := normalizeDownloadDecryptionInfo(&DownloadDecryptionInfo{
+		Strategy:    "mp4_decryption_key",
+		Key:         "abcd",
+		InputFormat: "",
+	}, "")
+	if normalized == nil {
+		t.Fatal("expected descriptor to remain available")
+	}
+	if normalized.Strategy != genericFFmpegMOVDecryptionStrategy {
+		t.Fatalf("strategy = %q", normalized.Strategy)
+	}
+	if normalized.InputFormat != "mov" {
+		t.Fatalf("input format = %q", normalized.InputFormat)
+	}
+}
+
+func TestBuildOutputPathAddsExplicitOutputDirToAllowedDirs(t *testing.T) {
+	SetAllowedDownloadDirs(nil)
+
+	outputDir := t.TempDir()
+	outputPath := buildOutputPath(DownloadRequest{
+		TrackName:      "Song",
+		ArtistName:     "Artist",
+		OutputDir:      outputDir,
+		OutputExt:      ".flac",
+		FilenameFormat: "",
+	})
+
+	if !isPathInAllowedDirs(outputPath) {
+		t.Fatalf("expected output path %q to be allowed", outputPath)
+	}
+}
+
+func TestBuildOutputPathForExtensionAddsExplicitOutputPathDirToAllowedDirs(t *testing.T) {
+	SetAllowedDownloadDirs(nil)
+
+	outputDir := t.TempDir()
+	outputPath := filepath.Join(outputDir, "custom.flac")
+	ext := &loadedExtension{DataDir: t.TempDir()}
+
+	resolved := buildOutputPathForExtension(DownloadRequest{
+		OutputPath: outputPath,
+	}, ext)
+
+	if resolved != outputPath {
+		t.Fatalf("resolved output path = %q", resolved)
+	}
+	if !isPathInAllowedDirs(outputPath) {
+		t.Fatalf("expected output path %q to be allowed", outputPath)
+	}
+}
+
+func TestBuildOutputPathForExtensionUsesTempDirForFDOutput(t *testing.T) {
+	SetAllowedDownloadDirs(nil)
+
+	ext := &loadedExtension{DataDir: t.TempDir()}
+	resolved := buildOutputPathForExtension(DownloadRequest{
+		TrackName:  "Song",
+		ArtistName: "Artist",
+		OutputDir:  filepath.Join("Artist", "Album"),
+		OutputFD:   123,
+		OutputExt:  ".flac",
+	}, ext)
+
+	expectedBase := filepath.Join(ext.DataDir, "downloads")
+	if !isPathWithinBase(expectedBase, resolved) {
+		t.Fatalf("expected SAF extension output under %q, got %q", expectedBase, resolved)
+	}
+	if !isPathInAllowedDirs(resolved) {
+		t.Fatalf("expected resolved output path %q to be allowed", resolved)
+	}
+}
+
+func TestCanEmbedGenreLabelRequiresExistingAbsoluteLocalFile(t *testing.T) {
+	tempFile := filepath.Join(t.TempDir(), "track.flac")
+	if err := os.WriteFile(tempFile, []byte("fLaC"), 0644); err != nil {
+		t.Fatalf("failed to create temp file: %v", err)
+	}
+	tempM4A := filepath.Join(t.TempDir(), "track.m4a")
+	if err := os.WriteFile(tempM4A, []byte("not-flac"), 0644); err != nil {
+		t.Fatalf("failed to create temp m4a file: %v", err)
+	}
+
+	if canEmbedGenreLabel("relative.flac") {
+		t.Fatal("expected relative path to be rejected")
+	}
+	if canEmbedGenreLabel("content://example") {
+		t.Fatal("expected content URI to be rejected")
+	}
+	if canEmbedGenreLabel(filepath.Join(t.TempDir(), "missing.flac")) {
+		t.Fatal("expected missing file to be rejected")
+	}
+	if canEmbedGenreLabel(tempM4A) {
+		t.Fatalf("expected non-FLAC file %q to be rejected", tempM4A)
+	}
+	if !canEmbedGenreLabel(tempFile) {
+		t.Fatalf("expected existing absolute file %q to be accepted", tempFile)
+	}
+}
+
 func TestSearchTracksWithMetadataProvidersUsesPriorityAndDedupes(t *testing.T) {
 	originalPriority := GetMetadataProviderPriority()
 	originalSearch := searchBuiltInMetadataTracksFunc
@@ -27,7 +215,7 @@ func TestSearchTracksWithMetadataProvidersUsesPriorityAndDedupes(t *testing.T) {
 		searchBuiltInMetadataTracksFunc = originalSearch
 	}()
 
-	SetMetadataProviderPriority([]string{"qobuz", "tidal", "deezer"})
+	SetMetadataProviderPriority([]string{"qobuz", "tidal"})
 
 	var calls []string
 	searchBuiltInMetadataTracksFunc = func(providerID, query string, limit int) ([]ExtTrackMetadata, error) {
@@ -42,27 +230,23 @@ func TestSearchTracksWithMetadataProvidersUsesPriorityAndDedupes(t *testing.T) {
 				{ProviderID: "tidal", SpotifyID: "tidal:2", ISRC: "AAA111", Name: "Duplicate"},
 				{ProviderID: "tidal", SpotifyID: "tidal:3", ISRC: "BBB222", Name: "Second"},
 			}, nil
-		case "deezer":
-			return []ExtTrackMetadata{
-				{ProviderID: "deezer", SpotifyID: "deezer:4", ISRC: "CCC333", Name: "Third"},
-			}, nil
 		default:
 			return nil, nil
 		}
 	}
 
-	manager := GetExtensionManager()
+	manager := getExtensionManager()
 	tracks, err := manager.SearchTracksWithMetadataProviders("query", 3, false)
 	if err != nil {
 		t.Fatalf("SearchTracksWithMetadataProviders returned error: %v", err)
 	}
-	if len(tracks) != 3 {
-		t.Fatalf("unexpected track count: got %d want 3", len(tracks))
+	if len(tracks) != 2 {
+		t.Fatalf("unexpected track count: got %d want 2", len(tracks))
 	}
-	if tracks[0].ProviderID != "qobuz" || tracks[1].ProviderID != "tidal" || tracks[2].ProviderID != "deezer" {
+	if tracks[0].ProviderID != "qobuz" || tracks[1].ProviderID != "tidal" {
 		t.Fatalf("unexpected track provider order: %+v", tracks)
 	}
-	if len(calls) != 3 || calls[0] != "qobuz" || calls[1] != "tidal" || calls[2] != "deezer" {
+	if len(calls) != 2 || calls[0] != "qobuz" || calls[1] != "tidal" {
 		t.Fatalf("unexpected provider call order: %v", calls)
 	}
 }

go_backend/extension_runtime.go

@@ -5,6 +5,7 @@ import (
 	"net"
 	"net/http"
 	"net/url"
+	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -80,7 +81,7 @@ func SetExtensionTokens(extensionID string, accessToken, refreshToken string, ex
 	state.IsAuthenticated = accessToken != ""
 }
 
-type ExtensionRuntime struct {
+type extensionRuntime struct {
 	extensionID    string
 	manifest       *ExtensionManifest
 	settings       map[string]interface{}
@@ -123,10 +124,10 @@ var (
 	privateIPCacheMu sync.RWMutex
 )
 
-func NewExtensionRuntime(ext *LoadedExtension) *ExtensionRuntime {
+func newExtensionRuntime(ext *loadedExtension) *extensionRuntime {
 	jar, _ := newSimpleCookieJar()
 
-	runtime := &ExtensionRuntime{
+	runtime := &extensionRuntime{
 		extensionID:       ext.ID,
 		manifest:          ext.Manifest,
 		settings:          make(map[string]interface{}),
@@ -136,31 +137,92 @@ func NewExtensionRuntime(ext *LoadedExtension) *ExtensionRuntime {
 		storageFlushDelay: defaultStorageFlushDelay,
 	}
 
-	runtime.httpClient = newExtensionHTTPClient(ext, jar, 30*time.Second)
+	runtime.httpClient = newExtensionHTTPClient(ext, jar, extensionHTTPTimeout(ext, 30*time.Second))
 	runtime.downloadClient = newExtensionHTTPClient(ext, jar, DownloadTimeout)
 
 	return runtime
 }
 
-func (r *ExtensionRuntime) setActiveDownloadItemID(itemID string) {
+func extensionHTTPTimeout(ext *loadedExtension, fallback time.Duration) time.Duration {
+	if ext == nil || ext.Manifest == nil || ext.Manifest.Capabilities == nil {
+		return fallback
+	}
+
+	raw, ok := ext.Manifest.Capabilities["networkTimeoutSeconds"]
+	if !ok {
+		return fallback
+	}
+
+	seconds := parseExtensionTimeoutSeconds(raw)
+	if seconds <= 0 {
+		return fallback
+	}
+
+	if seconds < 5 {
+		seconds = 5
+	}
+	if seconds > 300 {
+		seconds = 300
+	}
+
+	return time.Duration(seconds) * time.Second
+}
+
+func parseExtensionTimeoutSeconds(raw interface{}) int {
+	switch v := raw.(type) {
+	case int:
+		return v
+	case int32:
+		return int(v)
+	case int64:
+		return int(v)
+	case float32:
+		return int(v)
+	case float64:
+		return int(v)
+	case string:
+		parsed, err := strconv.Atoi(strings.TrimSpace(v))
+		if err != nil {
+			return 0
+		}
+		return parsed
+	default:
+		return 0
+	}
+}
+
+func (r *extensionRuntime) setActiveDownloadItemID(itemID string) {
 	r.activeDownloadMu.Lock()
 	defer r.activeDownloadMu.Unlock()
 	r.activeDownloadItemID = strings.TrimSpace(itemID)
 }
 
-func (r *ExtensionRuntime) clearActiveDownloadItemID() {
+func (r *extensionRuntime) clearActiveDownloadItemID() {
 	r.activeDownloadMu.Lock()
 	defer r.activeDownloadMu.Unlock()
 	r.activeDownloadItemID = ""
 }
 
-func (r *ExtensionRuntime) getActiveDownloadItemID() string {
+func (r *extensionRuntime) getActiveDownloadItemID() string {
 	r.activeDownloadMu.RLock()
 	defer r.activeDownloadMu.RUnlock()
 	return r.activeDownloadItemID
 }
 
-func newExtensionHTTPClient(ext *LoadedExtension, jar http.CookieJar, timeout time.Duration) *http.Client {
+func (r *extensionRuntime) bindDownloadCancelContext(req *http.Request) *http.Request {
+	if req == nil {
+		return nil
+	}
+
+	itemID := r.getActiveDownloadItemID()
+	if itemID == "" {
+		return req
+	}
+
+	return req.WithContext(initDownloadCancel(itemID))
+}
+
+func newExtensionHTTPClient(ext *loadedExtension, jar http.CookieJar, timeout time.Duration) *http.Client {
 	// Extension sandbox enforces HTTPS-only domains. Do not apply global
 	// allow_http scheme downgrade here, because some extension APIs (e.g.
 	// spotify-web) will redirect http -> https and can end up in 301 loops.
@@ -329,11 +391,11 @@ func (j *simpleCookieJar) Cookies(u *url.URL) []*http.Cookie {
 	return j.cookies[u.Host]
 }
 
-func (r *ExtensionRuntime) SetSettings(settings map[string]interface{}) {
+func (r *extensionRuntime) SetSettings(settings map[string]interface{}) {
 	r.settings = settings
 }
 
-func (r *ExtensionRuntime) RegisterAPIs(vm *goja.Runtime) {
+func (r *extensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	r.vm = vm
 
 	httpObj := vm.NewObject()
@@ -377,7 +439,9 @@ func (r *ExtensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	fileObj.Set("exists", r.fileExists)
 	fileObj.Set("delete", r.fileDelete)
 	fileObj.Set("read", r.fileRead)
+	fileObj.Set("readBytes", r.fileReadBytes)
 	fileObj.Set("write", r.fileWrite)
+	fileObj.Set("writeBytes", r.fileWriteBytes)
 	fileObj.Set("copy", r.fileCopy)
 	fileObj.Set("move", r.fileMove)
 	fileObj.Set("getSize", r.fileGetSize)
@@ -407,8 +471,14 @@ func (r *ExtensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	utilsObj.Set("stringifyJSON", r.stringifyJSON)
 	utilsObj.Set("encrypt", r.cryptoEncrypt)
 	utilsObj.Set("decrypt", r.cryptoDecrypt)
+	utilsObj.Set("encryptBlockCipher", r.encryptBlockCipher)
+	utilsObj.Set("decryptBlockCipher", r.decryptBlockCipher)
 	utilsObj.Set("generateKey", r.cryptoGenerateKey)
 	utilsObj.Set("randomUserAgent", r.randomUserAgent)
+	utilsObj.Set("appVersion", r.appVersion)
+	utilsObj.Set("appUserAgent", r.appUserAgent)
+	utilsObj.Set("sleep", r.sleep)
+	utilsObj.Set("isDownloadCancelled", r.isDownloadCancelled)
 	vm.Set("utils", utilsObj)
 
 	logObj := vm.NewObject()

go_backend/extension_runtime_auth.go

@@ -52,7 +52,7 @@ func summarizeURLForLog(urlStr string) string {
 	return fmt.Sprintf("%s://%s%s", parsed.Scheme, parsed.Host, parsed.Path)
 }
 
-func (r *ExtensionRuntime) authOpenUrl(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) authOpenUrl(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -99,7 +99,7 @@ func (r *ExtensionRuntime) authOpenUrl(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *ExtensionRuntime) authGetCode(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) authGetCode(call goja.FunctionCall) goja.Value {
 	extensionAuthStateMu.RLock()
 	defer extensionAuthStateMu.RUnlock()
 
@@ -111,7 +111,7 @@ func (r *ExtensionRuntime) authGetCode(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(state.AuthCode)
 }
 
-func (r *ExtensionRuntime) authSetCode(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) authSetCode(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(false)
 	}
@@ -149,7 +149,7 @@ func (r *ExtensionRuntime) authSetCode(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(true)
 }
 
-func (r *ExtensionRuntime) authClear(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) authClear(call goja.FunctionCall) goja.Value {
 	extensionAuthStateMu.Lock()
 	delete(extensionAuthState, r.extensionID)
 	extensionAuthStateMu.Unlock()
@@ -162,7 +162,7 @@ func (r *ExtensionRuntime) authClear(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(true)
 }
 
-func (r *ExtensionRuntime) authIsAuthenticated(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) authIsAuthenticated(call goja.FunctionCall) goja.Value {
 	extensionAuthStateMu.RLock()
 	defer extensionAuthStateMu.RUnlock()
 
@@ -178,7 +178,7 @@ func (r *ExtensionRuntime) authIsAuthenticated(call goja.FunctionCall) goja.Valu
 	return r.vm.ToValue(state.IsAuthenticated)
 }
 
-func (r *ExtensionRuntime) authGetTokens(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) authGetTokens(call goja.FunctionCall) goja.Value {
 	extensionAuthStateMu.RLock()
 	defer extensionAuthStateMu.RUnlock()
 
@@ -228,7 +228,7 @@ func generatePKCEChallenge(verifier string) string {
 	return base64.RawURLEncoding.EncodeToString(hash[:])
 }
 
-func (r *ExtensionRuntime) authGeneratePKCE(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) authGeneratePKCE(call goja.FunctionCall) goja.Value {
 	length := 64
 	if len(call.Arguments) > 0 && !goja.IsUndefined(call.Arguments[0]) {
 		if l, ok := call.Arguments[0].Export().(float64); ok && l >= 43 && l <= 128 {
@@ -265,7 +265,7 @@ func (r *ExtensionRuntime) authGeneratePKCE(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *ExtensionRuntime) authGetPKCE(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) authGetPKCE(call goja.FunctionCall) goja.Value {
 	extensionAuthStateMu.RLock()
 	defer extensionAuthStateMu.RUnlock()
 
@@ -281,7 +281,7 @@ func (r *ExtensionRuntime) authGetPKCE(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *ExtensionRuntime) authStartOAuthWithPKCE(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) authStartOAuthWithPKCE(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -385,7 +385,7 @@ func (r *ExtensionRuntime) authStartOAuthWithPKCE(call goja.FunctionCall) goja.V
 	})
 }
 
-func (r *ExtensionRuntime) authExchangeCodeWithPKCE(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) authExchangeCodeWithPKCE(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -458,6 +458,7 @@ func (r *ExtensionRuntime) authExchangeCodeWithPKCE(call goja.FunctionCall) goja
 			"error":   err.Error(),
 		})
 	}
+	req = r.bindDownloadCancelContext(req)
 
 	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
 	req.Header.Set("User-Agent", "SpotiFLAC-Extension/1.0")

go_backend/extension_runtime_binary.go

@@ -0,0 +1,359 @@
+package gobackend
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"encoding/base64"
+	"encoding/hex"
+	"fmt"
+	"strings"
+
+	"github.com/dop251/goja"
+	"golang.org/x/crypto/blowfish"
+)
+
+type runtimeBlockCipherOptions struct {
+	Algorithm      string
+	Mode           string
+	Key            []byte
+	IV             []byte
+	InputEncoding  string
+	OutputEncoding string
+	Padding        string
+}
+
+func parseRuntimeOptionsArgument(call goja.FunctionCall, index int) map[string]interface{} {
+	if len(call.Arguments) <= index {
+		return nil
+	}
+
+	value := call.Arguments[index]
+	if goja.IsUndefined(value) || goja.IsNull(value) {
+		return nil
+	}
+
+	exported := value.Export()
+	if options, ok := exported.(map[string]interface{}); ok {
+		return options
+	}
+	return nil
+}
+
+func runtimeOptionString(options map[string]interface{}, key, defaultValue string) string {
+	if options == nil {
+		return defaultValue
+	}
+	raw, ok := options[key]
+	if !ok || raw == nil {
+		return defaultValue
+	}
+	switch value := raw.(type) {
+	case string:
+		if trimmed := strings.TrimSpace(value); trimmed != "" {
+			return trimmed
+		}
+	case []byte:
+		if len(value) > 0 {
+			return string(value)
+		}
+	}
+	return defaultValue
+}
+
+func runtimeOptionBool(options map[string]interface{}, key string, defaultValue bool) bool {
+	if options == nil {
+		return defaultValue
+	}
+	raw, ok := options[key]
+	if !ok || raw == nil {
+		return defaultValue
+	}
+	switch value := raw.(type) {
+	case bool:
+		return value
+	case int:
+		return value != 0
+	case int64:
+		return value != 0
+	case float64:
+		return value != 0
+	case string:
+		switch strings.ToLower(strings.TrimSpace(value)) {
+		case "1", "true", "yes", "on":
+			return true
+		case "0", "false", "no", "off":
+			return false
+		}
+	}
+	return defaultValue
+}
+
+func runtimeOptionInt64(options map[string]interface{}, key string, defaultValue int64) int64 {
+	if options == nil {
+		return defaultValue
+	}
+	raw, ok := options[key]
+	if !ok || raw == nil {
+		return defaultValue
+	}
+	switch value := raw.(type) {
+	case int:
+		return int64(value)
+	case int32:
+		return int64(value)
+	case int64:
+		return value
+	case float32:
+		return int64(value)
+	case float64:
+		return int64(value)
+	case string:
+		value = strings.TrimSpace(value)
+		if value == "" {
+			return defaultValue
+		}
+		var parsed int64
+		if _, err := fmt.Sscanf(value, "%d", &parsed); err == nil {
+			return parsed
+		}
+	}
+	return defaultValue
+}
+
+func runtimeOptionHasKey(options map[string]interface{}, key string) bool {
+	if options == nil {
+		return false
+	}
+	_, exists := options[key]
+	return exists
+}
+
+func decodeRuntimeBytesString(input, encoding string) ([]byte, error) {
+	switch strings.ToLower(strings.TrimSpace(encoding)) {
+	case "", "utf8", "utf-8", "text":
+		return []byte(input), nil
+	case "base64":
+		decoded, err := base64.StdEncoding.DecodeString(strings.TrimSpace(input))
+		if err != nil {
+			return nil, fmt.Errorf("invalid base64 data: %w", err)
+		}
+		return decoded, nil
+	case "hex":
+		decoded, err := hex.DecodeString(strings.TrimSpace(input))
+		if err != nil {
+			return nil, fmt.Errorf("invalid hex data: %w", err)
+		}
+		return decoded, nil
+	default:
+		return nil, fmt.Errorf("unsupported byte encoding: %s", encoding)
+	}
+}
+
+func decodeRuntimeBytesValue(raw interface{}, encoding string) ([]byte, error) {
+	switch value := raw.(type) {
+	case string:
+		return decodeRuntimeBytesString(value, encoding)
+	case []byte:
+		cloned := make([]byte, len(value))
+		copy(cloned, value)
+		return cloned, nil
+	case []interface{}:
+		decoded := make([]byte, len(value))
+		for i, item := range value {
+			switch num := item.(type) {
+			case int:
+				decoded[i] = byte(num)
+			case int64:
+				decoded[i] = byte(num)
+			case float64:
+				decoded[i] = byte(int(num))
+			default:
+				return nil, fmt.Errorf("unsupported byte array item at index %d", i)
+			}
+		}
+		return decoded, nil
+	default:
+		return nil, fmt.Errorf("unsupported byte payload type")
+	}
+}
+
+func encodeRuntimeBytes(data []byte, encoding string) (string, error) {
+	switch strings.ToLower(strings.TrimSpace(encoding)) {
+	case "", "base64":
+		return base64.StdEncoding.EncodeToString(data), nil
+	case "hex":
+		return hex.EncodeToString(data), nil
+	case "utf8", "utf-8", "text":
+		return string(data), nil
+	default:
+		return "", fmt.Errorf("unsupported byte encoding: %s", encoding)
+	}
+}
+
+func parseRuntimeBlockCipherOptions(options map[string]interface{}) (*runtimeBlockCipherOptions, error) {
+	parsed := &runtimeBlockCipherOptions{
+		Algorithm:      strings.ToLower(runtimeOptionString(options, "algorithm", "")),
+		Mode:           strings.ToLower(runtimeOptionString(options, "mode", "cbc")),
+		InputEncoding:  strings.ToLower(runtimeOptionString(options, "inputEncoding", "base64")),
+		OutputEncoding: strings.ToLower(runtimeOptionString(options, "outputEncoding", "base64")),
+		Padding:        strings.ToLower(runtimeOptionString(options, "padding", "none")),
+	}
+	if parsed.Algorithm == "" {
+		return nil, fmt.Errorf("algorithm is required")
+	}
+	if parsed.Mode == "" {
+		return nil, fmt.Errorf("mode is required")
+	}
+
+	key, err := decodeRuntimeBytesString(runtimeOptionString(options, "key", ""), runtimeOptionString(options, "keyEncoding", "utf8"))
+	if err != nil {
+		return nil, fmt.Errorf("invalid key: %w", err)
+	}
+	if len(key) == 0 {
+		return nil, fmt.Errorf("key is required")
+	}
+	parsed.Key = key
+
+	iv, err := decodeRuntimeBytesString(runtimeOptionString(options, "iv", ""), runtimeOptionString(options, "ivEncoding", "utf8"))
+	if err != nil {
+		return nil, fmt.Errorf("invalid iv: %w", err)
+	}
+	parsed.IV = iv
+	return parsed, nil
+}
+
+func newRuntimeBlockCipher(options *runtimeBlockCipherOptions) (cipher.Block, error) {
+	switch options.Algorithm {
+	case "blowfish":
+		return blowfish.NewCipher(options.Key)
+	case "aes":
+		return aes.NewCipher(options.Key)
+	default:
+		return nil, fmt.Errorf("unsupported block cipher algorithm: %s", options.Algorithm)
+	}
+}
+
+func applyPKCS7Padding(data []byte, blockSize int) []byte {
+	padding := blockSize - (len(data) % blockSize)
+	if padding == 0 {
+		padding = blockSize
+	}
+	out := make([]byte, len(data)+padding)
+	copy(out, data)
+	for i := len(data); i < len(out); i++ {
+		out[i] = byte(padding)
+	}
+	return out
+}
+
+func removePKCS7Padding(data []byte, blockSize int) ([]byte, error) {
+	if len(data) == 0 || len(data)%blockSize != 0 {
+		return nil, fmt.Errorf("invalid padded payload length")
+	}
+	padding := int(data[len(data)-1])
+	if padding <= 0 || padding > blockSize || padding > len(data) {
+		return nil, fmt.Errorf("invalid PKCS7 padding")
+	}
+	for i := len(data) - padding; i < len(data); i++ {
+		if int(data[i]) != padding {
+			return nil, fmt.Errorf("invalid PKCS7 padding")
+		}
+	}
+	return data[:len(data)-padding], nil
+}
+
+func (r *extensionRuntime) transformBlockCipher(call goja.FunctionCall, decrypt bool) goja.Value {
+	if len(call.Arguments) < 2 {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   "data and options are required",
+		})
+	}
+
+	options := parseRuntimeOptionsArgument(call, 1)
+	parsedOptions, err := parseRuntimeBlockCipherOptions(options)
+	if err != nil {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   err.Error(),
+		})
+	}
+	if parsedOptions.Mode != "cbc" {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   fmt.Sprintf("unsupported block cipher mode: %s", parsedOptions.Mode),
+		})
+	}
+
+	inputData, err := decodeRuntimeBytesValue(call.Arguments[0].Export(), parsedOptions.InputEncoding)
+	if err != nil {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   err.Error(),
+		})
+	}
+
+	block, err := newRuntimeBlockCipher(parsedOptions)
+	if err != nil {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   err.Error(),
+		})
+	}
+
+	if len(parsedOptions.IV) != block.BlockSize() {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   fmt.Sprintf("iv must be %d bytes for %s", block.BlockSize(), parsedOptions.Algorithm),
+		})
+	}
+
+	data := inputData
+	if !decrypt && parsedOptions.Padding == "pkcs7" {
+		data = applyPKCS7Padding(data, block.BlockSize())
+	}
+	if len(data)%block.BlockSize() != 0 {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   fmt.Sprintf("input length must be a multiple of %d bytes", block.BlockSize()),
+		})
+	}
+
+	output := make([]byte, len(data))
+	if decrypt {
+		cipher.NewCBCDecrypter(block, parsedOptions.IV).CryptBlocks(output, data)
+		if parsedOptions.Padding == "pkcs7" {
+			output, err = removePKCS7Padding(output, block.BlockSize())
+			if err != nil {
+				return r.vm.ToValue(map[string]interface{}{
+					"success": false,
+					"error":   err.Error(),
+				})
+			}
+		}
+	} else {
+		cipher.NewCBCEncrypter(block, parsedOptions.IV).CryptBlocks(output, data)
+	}
+
+	encoded, err := encodeRuntimeBytes(output, parsedOptions.OutputEncoding)
+	if err != nil {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   err.Error(),
+		})
+	}
+
+	return r.vm.ToValue(map[string]interface{}{
+		"success":    true,
+		"data":       encoded,
+		"block_size": block.BlockSize(),
+	})
+}
+
+func (r *extensionRuntime) encryptBlockCipher(call goja.FunctionCall) goja.Value {
+	return r.transformBlockCipher(call, false)
+}
+
+func (r *extensionRuntime) decryptBlockCipher(call goja.FunctionCall) goja.Value {
+	return r.transformBlockCipher(call, true)
+}

go_backend/extension_runtime_binary_test.go

@@ -0,0 +1,185 @@
+package gobackend
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/dop251/goja"
+)
+
+func newBinaryTestRuntime(t *testing.T, withFilePermission bool) *goja.Runtime {
+	t.Helper()
+
+	ext := &loadedExtension{
+		ID: "binary-test-ext",
+		Manifest: &ExtensionManifest{
+			Name: "binary-test-ext",
+			Permissions: ExtensionPermissions{
+				File: withFilePermission,
+			},
+		},
+		DataDir: t.TempDir(),
+	}
+
+	runtime := newExtensionRuntime(ext)
+	vm := goja.New()
+	runtime.RegisterAPIs(vm)
+	return vm
+}
+
+func decodeJSONResult[T any](t *testing.T, value goja.Value) T {
+	t.Helper()
+
+	var decoded T
+	if err := json.Unmarshal([]byte(value.String()), &decoded); err != nil {
+		t.Fatalf("failed to decode JSON result: %v", err)
+	}
+	return decoded
+}
+
+func TestExtensionRuntime_FileByteAPIs(t *testing.T) {
+	vm := newBinaryTestRuntime(t, true)
+
+	result, err := vm.RunString(`
+		(function() {
+			var first = file.writeBytes("bytes.bin", "AAEC", {encoding: "base64", truncate: true});
+			if (!first.success) throw new Error(first.error);
+
+			var second = file.writeBytes("bytes.bin", "0304ff", {encoding: "hex", append: true});
+			if (!second.success) throw new Error(second.error);
+
+			var all = file.readBytes("bytes.bin", {encoding: "hex"});
+			if (!all.success) throw new Error(all.error);
+
+			var slice = file.readBytes("bytes.bin", {offset: 2, length: 2, encoding: "hex"});
+			if (!slice.success) throw new Error(slice.error);
+
+			var tail = file.readBytes("bytes.bin", {offset: 6, length: 4, encoding: "hex"});
+			if (!tail.success) throw new Error(tail.error);
+
+			return JSON.stringify({
+				all: all.data,
+				slice: slice.data,
+				size: all.size,
+				sliceBytes: slice.bytes_read,
+				sliceEof: slice.eof,
+				tailBytes: tail.bytes_read,
+				tailEof: tail.eof
+			});
+		})()
+	`)
+	if err != nil {
+		t.Fatalf("file byte APIs failed: %v", err)
+	}
+
+	decoded := decodeJSONResult[struct {
+		All        string `json:"all"`
+		Slice      string `json:"slice"`
+		Size       int64  `json:"size"`
+		SliceBytes int    `json:"sliceBytes"`
+		SliceEof   bool   `json:"sliceEof"`
+		TailBytes  int    `json:"tailBytes"`
+		TailEof    bool   `json:"tailEof"`
+	}](t, result)
+
+	if decoded.All != "0001020304ff" {
+		t.Fatalf("all = %q", decoded.All)
+	}
+	if decoded.Slice != "0203" {
+		t.Fatalf("slice = %q", decoded.Slice)
+	}
+	if decoded.Size != 6 {
+		t.Fatalf("size = %d", decoded.Size)
+	}
+	if decoded.SliceBytes != 2 {
+		t.Fatalf("slice bytes = %d", decoded.SliceBytes)
+	}
+	if decoded.SliceEof {
+		t.Fatal("slice should not be EOF")
+	}
+	if decoded.TailBytes != 0 || !decoded.TailEof {
+		t.Fatalf("tail read mismatch: bytes=%d eof=%v", decoded.TailBytes, decoded.TailEof)
+	}
+}
+
+func TestExtensionRuntime_BlockCipherCBCSupportsBlowfish(t *testing.T) {
+	vm := newBinaryTestRuntime(t, false)
+
+	result, err := vm.RunString(`
+		(function() {
+			var options = {
+				algorithm: "blowfish",
+				mode: "cbc",
+				key: "0123456789ABCDEFF0E1D2C3B4A59687",
+				keyEncoding: "hex",
+				iv: "0001020304050607",
+				ivEncoding: "hex",
+				inputEncoding: "hex",
+				outputEncoding: "hex",
+				padding: "none"
+			};
+			var enc = utils.encryptBlockCipher("00112233445566778899aabbccddeeff", options);
+			if (!enc.success) throw new Error(enc.error);
+			var dec = utils.decryptBlockCipher(enc.data, options);
+			if (!dec.success) throw new Error(dec.error);
+			return JSON.stringify({enc: enc.data, dec: dec.data});
+		})()
+	`)
+	if err != nil {
+		t.Fatalf("blowfish block cipher failed: %v", err)
+	}
+
+	decoded := decodeJSONResult[struct {
+		Enc string `json:"enc"`
+		Dec string `json:"dec"`
+	}](t, result)
+
+	if decoded.Dec != "00112233445566778899aabbccddeeff" {
+		t.Fatalf("dec = %q", decoded.Dec)
+	}
+	if decoded.Enc == decoded.Dec {
+		t.Fatal("expected ciphertext to differ from plaintext")
+	}
+}
+
+func TestExtensionRuntime_BlockCipherCBCSupportsAES(t *testing.T) {
+	vm := newBinaryTestRuntime(t, false)
+
+	result, err := vm.RunString(`
+		(function() {
+			var options = {
+				algorithm: "aes",
+				mode: "cbc",
+				key: "000102030405060708090a0b0c0d0e0f",
+				keyEncoding: "hex",
+				iv: "0f0e0d0c0b0a09080706050403020100",
+				ivEncoding: "hex",
+				inputEncoding: "utf8",
+				outputEncoding: "base64",
+				padding: "pkcs7"
+			};
+			var enc = utils.encryptBlockCipher("hello generic cbc", options);
+			if (!enc.success) throw new Error(enc.error);
+			var dec = utils.decryptBlockCipher(enc.data, {
+				algorithm: "aes",
+				mode: "cbc",
+				key: options.key,
+				keyEncoding: options.keyEncoding,
+				iv: options.iv,
+				ivEncoding: options.ivEncoding,
+				inputEncoding: "base64",
+				outputEncoding: "utf8",
+				padding: "pkcs7"
+			});
+			if (!dec.success) throw new Error(dec.error);
+			return dec.data;
+		})()
+	`)
+	if err != nil {
+		t.Fatalf("aes block cipher failed: %v", err)
+	}
+
+	if result.String() != "hello generic cbc" {
+		t.Fatalf("unexpected decrypted value: %q", result.String())
+	}
+}

go_backend/extension_runtime_ffmpeg.go

@@ -50,7 +50,7 @@ func ClearFFmpegCommand(commandID string) {
 	delete(ffmpegCommands, commandID)
 }
 
-func (r *ExtensionRuntime) ffmpegExecute(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) ffmpegExecute(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -107,7 +107,7 @@ func (r *ExtensionRuntime) ffmpegExecute(call goja.FunctionCall) goja.Value {
 	}
 }
 
-func (r *ExtensionRuntime) ffmpegGetInfo(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) ffmpegGetInfo(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -134,7 +134,7 @@ func (r *ExtensionRuntime) ffmpegGetInfo(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *ExtensionRuntime) ffmpegConvert(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) ffmpegConvert(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,

go_backend/extension_runtime_file.go

@@ -71,7 +71,7 @@ func isPathWithinBase(baseDir, targetPath string) bool {
 	return true
 }
 
-func (r *ExtensionRuntime) validatePath(path string) (string, error) {
+func (r *extensionRuntime) validatePath(path string) (string, error) {
 	if !r.manifest.Permissions.File {
 		return "", fmt.Errorf("file access denied: extension does not have 'file' permission")
 	}
@@ -106,7 +106,7 @@ func (r *ExtensionRuntime) validatePath(path string) (string, error) {
 	return absPath, nil
 }
 
-func (r *ExtensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -166,6 +166,7 @@ func (r *ExtensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 			"error":   err.Error(),
 		})
 	}
+	req = r.bindDownloadCancelContext(req)
 
 	for k, v := range headers {
 		req.Header.Set(k, v)
@@ -271,7 +272,7 @@ func (r *ExtensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *ExtensionRuntime) fileExists(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) fileExists(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(false)
 	}
@@ -286,7 +287,7 @@ func (r *ExtensionRuntime) fileExists(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(err == nil)
 }
 
-func (r *ExtensionRuntime) fileDelete(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) fileDelete(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -315,7 +316,7 @@ func (r *ExtensionRuntime) fileDelete(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *ExtensionRuntime) fileRead(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) fileRead(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -346,7 +347,105 @@ func (r *ExtensionRuntime) fileRead(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *ExtensionRuntime) fileWrite(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) fileReadBytes(call goja.FunctionCall) goja.Value {
+	if len(call.Arguments) < 1 {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   "path is required",
+		})
+	}
+
+	path := call.Arguments[0].String()
+	fullPath, err := r.validatePath(path)
+	if err != nil {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   err.Error(),
+		})
+	}
+
+	options := parseRuntimeOptionsArgument(call, 1)
+	offset := runtimeOptionInt64(options, "offset", 0)
+	length := runtimeOptionInt64(options, "length", -1)
+	encoding := runtimeOptionString(options, "encoding", "base64")
+	if offset < 0 {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   "offset must be >= 0",
+		})
+	}
+
+	file, err := os.Open(fullPath)
+	if err != nil {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   err.Error(),
+		})
+	}
+	defer file.Close()
+
+	info, err := file.Stat()
+	if err != nil {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   err.Error(),
+		})
+	}
+
+	size := info.Size()
+	if offset > size {
+		offset = size
+	}
+	if _, err := file.Seek(offset, io.SeekStart); err != nil {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   fmt.Sprintf("failed to seek file: %v", err),
+		})
+	}
+
+	var data []byte
+	switch {
+	case length == 0:
+		data = []byte{}
+	case length > 0:
+		buf := make([]byte, int(length))
+		n, readErr := file.Read(buf)
+		if readErr != nil && readErr != io.EOF {
+			return r.vm.ToValue(map[string]interface{}{
+				"success": false,
+				"error":   fmt.Sprintf("failed to read file: %v", readErr),
+			})
+		}
+		data = buf[:n]
+	default:
+		data, err = io.ReadAll(file)
+		if err != nil {
+			return r.vm.ToValue(map[string]interface{}{
+				"success": false,
+				"error":   fmt.Sprintf("failed to read file: %v", err),
+			})
+		}
+	}
+
+	encoded, err := encodeRuntimeBytes(data, encoding)
+	if err != nil {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   err.Error(),
+		})
+	}
+
+	return r.vm.ToValue(map[string]interface{}{
+		"success":    true,
+		"data":       encoded,
+		"bytes_read": len(data),
+		"offset":     offset,
+		"size":       size,
+		"eof":        offset+int64(len(data)) >= size,
+	})
+}
+
+func (r *extensionRuntime) fileWrite(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -386,7 +485,108 @@ func (r *ExtensionRuntime) fileWrite(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *ExtensionRuntime) fileCopy(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) fileWriteBytes(call goja.FunctionCall) goja.Value {
+	if len(call.Arguments) < 2 {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   "path and data are required",
+		})
+	}
+
+	path := call.Arguments[0].String()
+	fullPath, err := r.validatePath(path)
+	if err != nil {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   err.Error(),
+		})
+	}
+
+	options := parseRuntimeOptionsArgument(call, 2)
+	appendMode := runtimeOptionBool(options, "append", false)
+	truncate := runtimeOptionBool(options, "truncate", false)
+	hasOffset := runtimeOptionHasKey(options, "offset")
+	offset := runtimeOptionInt64(options, "offset", 0)
+	encoding := runtimeOptionString(options, "encoding", "base64")
+
+	if appendMode && hasOffset {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   "append and offset cannot be used together",
+		})
+	}
+	if offset < 0 {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   "offset must be >= 0",
+		})
+	}
+
+	data, err := decodeRuntimeBytesValue(call.Arguments[1].Export(), encoding)
+	if err != nil {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   err.Error(),
+		})
+	}
+
+	dir := filepath.Dir(fullPath)
+	if err := os.MkdirAll(dir, 0755); err != nil {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   fmt.Sprintf("failed to create directory: %v", err),
+		})
+	}
+
+	flags := os.O_CREATE | os.O_WRONLY
+	if appendMode {
+		flags |= os.O_APPEND
+	}
+	if truncate {
+		flags |= os.O_TRUNC
+	}
+
+	file, err := os.OpenFile(fullPath, flags, 0644)
+	if err != nil {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   err.Error(),
+		})
+	}
+	defer file.Close()
+
+	if hasOffset && !appendMode {
+		if _, err := file.Seek(offset, io.SeekStart); err != nil {
+			return r.vm.ToValue(map[string]interface{}{
+				"success": false,
+				"error":   fmt.Sprintf("failed to seek file: %v", err),
+			})
+		}
+	}
+
+	written, err := file.Write(data)
+	if err != nil {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   err.Error(),
+		})
+	}
+
+	info, statErr := file.Stat()
+	size := int64(0)
+	if statErr == nil {
+		size = info.Size()
+	}
+
+	return r.vm.ToValue(map[string]interface{}{
+		"success":       true,
+		"path":          fullPath,
+		"bytes_written": written,
+		"size":          size,
+	})
+}
+
+func (r *extensionRuntime) fileCopy(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -459,7 +659,7 @@ func (r *ExtensionRuntime) fileCopy(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *ExtensionRuntime) fileMove(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) fileMove(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -507,7 +707,7 @@ func (r *ExtensionRuntime) fileMove(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *ExtensionRuntime) fileGetSize(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) fileGetSize(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,

go_backend/extension_runtime_http.go

@@ -17,7 +17,7 @@ type HTTPResponse struct {
 	Headers    map[string]string `json:"headers"`
 }
 
-func (r *ExtensionRuntime) validateDomain(urlStr string) error {
+func (r *extensionRuntime) validateDomain(urlStr string) error {
 	parsed, err := url.Parse(urlStr)
 	if err != nil {
 		return fmt.Errorf("invalid URL: %w", err)
@@ -49,7 +49,7 @@ func (r *ExtensionRuntime) validateDomain(urlStr string) error {
 	return nil
 }
 
-func (r *ExtensionRuntime) httpGet(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) httpGet(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"error": "URL is required",
@@ -81,6 +81,7 @@ func (r *ExtensionRuntime) httpGet(call goja.FunctionCall) goja.Value {
 			"error": err.Error(),
 		})
 	}
+	req = r.bindDownloadCancelContext(req)
 
 	for k, v := range headers {
 		req.Header.Set(k, v)
@@ -124,7 +125,7 @@ func (r *ExtensionRuntime) httpGet(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"error": "URL is required",
@@ -175,6 +176,7 @@ func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 			"error": err.Error(),
 		})
 	}
+	req = r.bindDownloadCancelContext(req)
 
 	for k, v := range headers {
 		req.Header.Set(k, v)
@@ -221,7 +223,7 @@ func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *ExtensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"error": "URL is required",
@@ -284,6 +286,7 @@ func (r *ExtensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 			"error": err.Error(),
 		})
 	}
+	req = r.bindDownloadCancelContext(req)
 
 	for k, v := range headers {
 		req.Header.Set(k, v)
@@ -330,19 +333,19 @@ func (r *ExtensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *ExtensionRuntime) httpPut(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) httpPut(call goja.FunctionCall) goja.Value {
 	return r.httpMethodShortcut("PUT", call)
 }
 
-func (r *ExtensionRuntime) httpDelete(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) httpDelete(call goja.FunctionCall) goja.Value {
 	return r.httpMethodShortcut("DELETE", call)
 }
 
-func (r *ExtensionRuntime) httpPatch(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) httpPatch(call goja.FunctionCall) goja.Value {
 	return r.httpMethodShortcut("PATCH", call)
 }
 
-func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) httpMethodShortcut(method string, call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"error": "URL is required",
@@ -410,6 +413,7 @@ func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionC
 			"error": err.Error(),
 		})
 	}
+	req = r.bindDownloadCancelContext(req)
 
 	for k, v := range headers {
 		req.Header.Set(k, v)
@@ -455,7 +459,7 @@ func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionC
 	})
 }
 
-func (r *ExtensionRuntime) httpClearCookies(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) httpClearCookies(call goja.FunctionCall) goja.Value {
 	if jar, ok := r.cookieJar.(*simpleCookieJar); ok {
 		jar.mu.Lock()
 		jar.cookies = make(map[string][]*http.Cookie)

go_backend/extension_runtime_matching.go

@@ -6,7 +6,7 @@ import (
 	"github.com/dop251/goja"
 )
 
-func (r *ExtensionRuntime) matchingCompareStrings(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) matchingCompareStrings(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(0.0)
 	}
@@ -22,7 +22,7 @@ func (r *ExtensionRuntime) matchingCompareStrings(call goja.FunctionCall) goja.V
 	return r.vm.ToValue(similarity)
 }
 
-func (r *ExtensionRuntime) matchingCompareDuration(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) matchingCompareDuration(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(false)
 	}
@@ -43,7 +43,7 @@ func (r *ExtensionRuntime) matchingCompareDuration(call goja.FunctionCall) goja.
 	return r.vm.ToValue(diff <= tolerance)
 }
 
-func (r *ExtensionRuntime) matchingNormalizeString(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) matchingNormalizeString(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
 	}

go_backend/extension_runtime_polyfills.go

@@ -12,7 +12,7 @@ import (
 	"github.com/dop251/goja"
 )
 
-func (r *ExtensionRuntime) fetchPolyfill(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) fetchPolyfill(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.createFetchError("URL is required")
 	}
@@ -69,6 +69,7 @@ func (r *ExtensionRuntime) fetchPolyfill(call goja.FunctionCall) goja.Value {
 	if err != nil {
 		return r.createFetchError(err.Error())
 	}
+	req = r.bindDownloadCancelContext(req)
 
 	for k, v := range headers {
 		req.Header.Set(k, v)
@@ -133,7 +134,7 @@ func (r *ExtensionRuntime) fetchPolyfill(call goja.FunctionCall) goja.Value {
 	return responseObj
 }
 
-func (r *ExtensionRuntime) createFetchError(message string) goja.Value {
+func (r *extensionRuntime) createFetchError(message string) goja.Value {
 	errorObj := r.vm.NewObject()
 	errorObj.Set("ok", false)
 	errorObj.Set("status", 0)
@@ -148,7 +149,7 @@ func (r *ExtensionRuntime) createFetchError(message string) goja.Value {
 	return errorObj
 }
 
-func (r *ExtensionRuntime) atobPolyfill(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) atobPolyfill(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
 	}
@@ -164,7 +165,7 @@ func (r *ExtensionRuntime) atobPolyfill(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(string(decoded))
 }
 
-func (r *ExtensionRuntime) btoaPolyfill(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) btoaPolyfill(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
 	}
@@ -172,7 +173,7 @@ func (r *ExtensionRuntime) btoaPolyfill(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(base64.StdEncoding.EncodeToString([]byte(input)))
 }
 
-func (r *ExtensionRuntime) registerTextEncoderDecoder(vm *goja.Runtime) {
+func (r *extensionRuntime) registerTextEncoderDecoder(vm *goja.Runtime) {
 	vm.Set("TextEncoder", func(call goja.ConstructorCall) *goja.Object {
 		encoder := call.This
 		encoder.Set("encoding", "utf-8")
@@ -252,7 +253,7 @@ func (r *ExtensionRuntime) registerTextEncoderDecoder(vm *goja.Runtime) {
 	})
 }
 
-func (r *ExtensionRuntime) registerURLClass(vm *goja.Runtime) {
+func (r *extensionRuntime) registerURLClass(vm *goja.Runtime) {
 	vm.Set("URL", func(call goja.ConstructorCall) *goja.Object {
 		urlObj := call.This
 
@@ -416,7 +417,7 @@ func (r *ExtensionRuntime) registerURLClass(vm *goja.Runtime) {
 	})
 }
 
-func (r *ExtensionRuntime) registerJSONGlobal(vm *goja.Runtime) {
+func (r *extensionRuntime) registerJSONGlobal(vm *goja.Runtime) {
 	jsonScript := `
 		if (typeof JSON === 'undefined') {
 			var JSON = {

go_backend/extension_runtime_storage.go

@@ -21,7 +21,7 @@ const (
 	storageFlushRetryDelay   = 2 * time.Second
 )
 
-func (r *ExtensionRuntime) getStoragePath() string {
+func (r *extensionRuntime) getStoragePath() string {
 	return filepath.Join(r.dataDir, "storage.json")
 }
 
@@ -36,7 +36,7 @@ func cloneInterfaceMap(src map[string]interface{}) map[string]interface{} {
 	return dst
 }
 
-func (r *ExtensionRuntime) ensureStorageLoaded() error {
+func (r *extensionRuntime) ensureStorageLoaded() error {
 	r.storageMu.RLock()
 	if r.storageLoaded {
 		r.storageMu.RUnlock()
@@ -74,7 +74,7 @@ func (r *ExtensionRuntime) ensureStorageLoaded() error {
 	return nil
 }
 
-func (r *ExtensionRuntime) loadStorage() (map[string]interface{}, error) {
+func (r *extensionRuntime) loadStorage() (map[string]interface{}, error) {
 	if err := r.ensureStorageLoaded(); err != nil {
 		return nil, err
 	}
@@ -84,7 +84,7 @@ func (r *ExtensionRuntime) loadStorage() (map[string]interface{}, error) {
 	return cloneInterfaceMap(r.storageCache), nil
 }
 
-func (r *ExtensionRuntime) queueStorageFlushLocked(delay time.Duration) {
+func (r *extensionRuntime) queueStorageFlushLocked(delay time.Duration) {
 	if r.storageClosed {
 		return
 	}
@@ -94,7 +94,7 @@ func (r *ExtensionRuntime) queueStorageFlushLocked(delay time.Duration) {
 	r.storageTimer = time.AfterFunc(delay, r.flushStorageDirtyAsync)
 }
 
-func (r *ExtensionRuntime) persistStorageSnapshot(storage map[string]interface{}) error {
+func (r *extensionRuntime) persistStorageSnapshot(storage map[string]interface{}) error {
 	data, err := json.Marshal(storage)
 	if err != nil {
 		return err
@@ -106,13 +106,13 @@ func (r *ExtensionRuntime) persistStorageSnapshot(storage map[string]interface{}
 	return os.WriteFile(r.getStoragePath(), data, 0600)
 }
 
-func (r *ExtensionRuntime) flushStorageDirtyAsync() {
+func (r *extensionRuntime) flushStorageDirtyAsync() {
 	if err := r.flushStorageDirty(); err != nil {
 		GoLog("[Extension:%s] Storage flush error: %v\n", r.extensionID, err)
 	}
 }
 
-func (r *ExtensionRuntime) flushStorageDirty() error {
+func (r *extensionRuntime) flushStorageDirty() error {
 	r.storageMu.Lock()
 	if r.storageClosed {
 		r.storageTimer = nil
@@ -140,7 +140,7 @@ func (r *ExtensionRuntime) flushStorageDirty() error {
 	return nil
 }
 
-func (r *ExtensionRuntime) flushStorageNow() error {
+func (r *extensionRuntime) flushStorageNow() error {
 	r.storageMu.Lock()
 	if r.storageTimer != nil {
 		r.storageTimer.Stop()
@@ -157,7 +157,7 @@ func (r *ExtensionRuntime) flushStorageNow() error {
 	return r.persistStorageSnapshot(snapshot)
 }
 
-func (r *ExtensionRuntime) closeStorageFlusher() {
+func (r *extensionRuntime) closeStorageFlusher() {
 	r.storageMu.Lock()
 	r.storageClosed = true
 	r.storageDirty = false
@@ -168,7 +168,7 @@ func (r *ExtensionRuntime) closeStorageFlusher() {
 	r.storageMu.Unlock()
 }
 
-func (r *ExtensionRuntime) storageGet(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) storageGet(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return goja.Undefined()
 	}
@@ -193,7 +193,7 @@ func (r *ExtensionRuntime) storageGet(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(value)
 }
 
-func (r *ExtensionRuntime) storageSet(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) storageSet(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(false)
 	}
@@ -225,7 +225,7 @@ func (r *ExtensionRuntime) storageSet(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(true)
 }
 
-func (r *ExtensionRuntime) storageRemove(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) storageRemove(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(false)
 	}
@@ -254,15 +254,15 @@ func (r *ExtensionRuntime) storageRemove(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(true)
 }
 
-func (r *ExtensionRuntime) getCredentialsPath() string {
+func (r *extensionRuntime) getCredentialsPath() string {
 	return filepath.Join(r.dataDir, ".credentials.enc")
 }
 
-func (r *ExtensionRuntime) getSaltPath() string {
+func (r *extensionRuntime) getSaltPath() string {
 	return filepath.Join(r.dataDir, ".cred_salt")
 }
 
-func (r *ExtensionRuntime) getOrCreateSalt() ([]byte, error) {
+func (r *extensionRuntime) getOrCreateSalt() ([]byte, error) {
 	saltPath := r.getSaltPath()
 
 	salt, err := os.ReadFile(saltPath)
@@ -282,7 +282,7 @@ func (r *ExtensionRuntime) getOrCreateSalt() ([]byte, error) {
 	return salt, nil
 }
 
-func (r *ExtensionRuntime) getEncryptionKey() ([]byte, error) {
+func (r *extensionRuntime) getEncryptionKey() ([]byte, error) {
 	salt, err := r.getOrCreateSalt()
 	if err != nil {
 		return nil, err
@@ -293,7 +293,7 @@ func (r *ExtensionRuntime) getEncryptionKey() ([]byte, error) {
 	return hash[:], nil
 }
 
-func (r *ExtensionRuntime) ensureCredentialsLoaded() error {
+func (r *extensionRuntime) ensureCredentialsLoaded() error {
 	r.credentialsMu.RLock()
 	if r.credentialsLoaded {
 		r.credentialsMu.RUnlock()
@@ -340,7 +340,7 @@ func (r *ExtensionRuntime) ensureCredentialsLoaded() error {
 	return nil
 }
 
-func (r *ExtensionRuntime) loadCredentials() (map[string]interface{}, error) {
+func (r *extensionRuntime) loadCredentials() (map[string]interface{}, error) {
 	if err := r.ensureCredentialsLoaded(); err != nil {
 		return nil, err
 	}
@@ -350,7 +350,7 @@ func (r *ExtensionRuntime) loadCredentials() (map[string]interface{}, error) {
 	return cloneInterfaceMap(r.credentialsCache), nil
 }
 
-func (r *ExtensionRuntime) saveCredentials(creds map[string]interface{}) error {
+func (r *extensionRuntime) saveCredentials(creds map[string]interface{}) error {
 	data, err := json.Marshal(creds)
 	if err != nil {
 		return err
@@ -377,7 +377,7 @@ func (r *ExtensionRuntime) saveCredentials(creds map[string]interface{}) error {
 	return nil
 }
 
-func (r *ExtensionRuntime) credentialsStore(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) credentialsStore(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -414,7 +414,7 @@ func (r *ExtensionRuntime) credentialsStore(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *ExtensionRuntime) credentialsGet(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) credentialsGet(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return goja.Undefined()
 	}
@@ -439,7 +439,7 @@ func (r *ExtensionRuntime) credentialsGet(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(value)
 }
 
-func (r *ExtensionRuntime) credentialsRemove(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) credentialsRemove(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(false)
 	}
@@ -464,7 +464,7 @@ func (r *ExtensionRuntime) credentialsRemove(call goja.FunctionCall) goja.Value
 	return r.vm.ToValue(true)
 }
 
-func (r *ExtensionRuntime) credentialsHas(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) credentialsHas(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(false)
 	}

go_backend/extension_runtime_storage_test.go

@@ -11,7 +11,7 @@ import (
 	"github.com/dop251/goja"
 )
 
-func setStorageValue(t *testing.T, runtime *ExtensionRuntime, key string, value interface{}) {
+func setStorageValue(t *testing.T, runtime *extensionRuntime, key string, value interface{}) {
 	t.Helper()
 	result := runtime.storageSet(goja.FunctionCall{
 		Arguments: []goja.Value{
@@ -39,7 +39,7 @@ func readStorageMap(t *testing.T, storagePath string) map[string]interface{} {
 }
 
 func TestExtensionRuntimeStorage_DebouncedWriteCompactJSON(t *testing.T) {
-	ext := &LoadedExtension{
+	ext := &loadedExtension{
 		ID: "storage-test",
 		Manifest: &ExtensionManifest{
 			Name: "storage-test",
@@ -47,7 +47,7 @@ func TestExtensionRuntimeStorage_DebouncedWriteCompactJSON(t *testing.T) {
 		DataDir: t.TempDir(),
 	}
 
-	runtime := NewExtensionRuntime(ext)
+	runtime := newExtensionRuntime(ext)
 	runtime.storageFlushDelay = 25 * time.Millisecond
 	runtime.RegisterAPIs(goja.New())
 
@@ -86,7 +86,7 @@ func TestExtensionRuntimeStorage_DebouncedWriteCompactJSON(t *testing.T) {
 }
 
 func TestUnloadExtension_FlushesPendingStorage(t *testing.T) {
-	ext := &LoadedExtension{
+	ext := &loadedExtension{
 		ID: "unload-storage-test",
 		Manifest: &ExtensionManifest{
 			Name: "unload-storage-test",
@@ -95,13 +95,13 @@ func TestUnloadExtension_FlushesPendingStorage(t *testing.T) {
 		VM:      goja.New(),
 	}
 
-	runtime := NewExtensionRuntime(ext)
+	runtime := newExtensionRuntime(ext)
 	runtime.storageFlushDelay = time.Hour
 	runtime.RegisterAPIs(ext.VM)
 	ext.runtime = runtime
 
-	manager := &ExtensionManager{
-		extensions: map[string]*LoadedExtension{
+	manager := &extensionManager{
+		extensions: map[string]*loadedExtension{
 			ext.ID: ext,
 		},
 	}

go_backend/extension_runtime_utils.go

@@ -16,7 +16,7 @@ import (
 	"github.com/dop251/goja"
 )
 
-func (r *ExtensionRuntime) base64Encode(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) base64Encode(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
 	}
@@ -24,7 +24,7 @@ func (r *ExtensionRuntime) base64Encode(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(base64.StdEncoding.EncodeToString([]byte(input)))
 }
 
-func (r *ExtensionRuntime) base64Decode(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) base64Decode(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
 	}
@@ -36,7 +36,7 @@ func (r *ExtensionRuntime) base64Decode(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(string(decoded))
 }
 
-func (r *ExtensionRuntime) md5Hash(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) md5Hash(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
 	}
@@ -45,7 +45,7 @@ func (r *ExtensionRuntime) md5Hash(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(hex.EncodeToString(hash[:]))
 }
 
-func (r *ExtensionRuntime) sha256Hash(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) sha256Hash(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
 	}
@@ -54,7 +54,7 @@ func (r *ExtensionRuntime) sha256Hash(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(hex.EncodeToString(hash[:]))
 }
 
-func (r *ExtensionRuntime) hmacSHA256(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) hmacSHA256(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue("")
 	}
@@ -66,7 +66,7 @@ func (r *ExtensionRuntime) hmacSHA256(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(hex.EncodeToString(mac.Sum(nil)))
 }
 
-func (r *ExtensionRuntime) hmacSHA256Base64(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) hmacSHA256Base64(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue("")
 	}
@@ -78,7 +78,7 @@ func (r *ExtensionRuntime) hmacSHA256Base64(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(base64.StdEncoding.EncodeToString(mac.Sum(nil)))
 }
 
-func (r *ExtensionRuntime) hmacSHA1(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) hmacSHA1(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue([]byte{})
 	}
@@ -130,7 +130,7 @@ func (r *ExtensionRuntime) hmacSHA1(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(jsArray)
 }
 
-func (r *ExtensionRuntime) parseJSON(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) parseJSON(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return goja.Undefined()
 	}
@@ -145,7 +145,7 @@ func (r *ExtensionRuntime) parseJSON(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(result)
 }
 
-func (r *ExtensionRuntime) stringifyJSON(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) stringifyJSON(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
 	}
@@ -160,7 +160,7 @@ func (r *ExtensionRuntime) stringifyJSON(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(string(data))
 }
 
-func (r *ExtensionRuntime) cryptoEncrypt(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) cryptoEncrypt(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -187,7 +187,7 @@ func (r *ExtensionRuntime) cryptoEncrypt(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *ExtensionRuntime) cryptoDecrypt(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) cryptoDecrypt(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -222,7 +222,7 @@ func (r *ExtensionRuntime) cryptoDecrypt(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *ExtensionRuntime) cryptoGenerateKey(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) cryptoGenerateKey(call goja.FunctionCall) goja.Value {
 	length := 32
 	if len(call.Arguments) > 0 && !goja.IsUndefined(call.Arguments[0]) {
 		if l, ok := call.Arguments[0].Export().(float64); ok {
@@ -245,35 +245,98 @@ func (r *ExtensionRuntime) cryptoGenerateKey(call goja.FunctionCall) goja.Value
 	})
 }
 
-func (r *ExtensionRuntime) randomUserAgent(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) randomUserAgent(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(getRandomUserAgent())
 }
 
-func (r *ExtensionRuntime) logDebug(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) appVersion(call goja.FunctionCall) goja.Value {
+	return r.vm.ToValue(GetAppVersion())
+}
+
+func (r *extensionRuntime) appUserAgent(call goja.FunctionCall) goja.Value {
+	return r.vm.ToValue(appUserAgent())
+}
+
+func (r *extensionRuntime) sleep(call goja.FunctionCall) goja.Value {
+	if len(call.Arguments) < 1 {
+		return r.vm.ToValue(true)
+	}
+
+	sleepMs := 0
+	switch value := call.Arguments[0].Export().(type) {
+	case int64:
+		sleepMs = int(value)
+	case int32:
+		sleepMs = int(value)
+	case int:
+		sleepMs = value
+	case float64:
+		sleepMs = int(value)
+	default:
+		sleepMs = 0
+	}
+
+	if sleepMs <= 0 {
+		return r.vm.ToValue(true)
+	}
+	if sleepMs > 5*60*1000 {
+		sleepMs = 5 * 60 * 1000
+	}
+
+	itemID := r.getActiveDownloadItemID()
+	deadline := time.Now().Add(time.Duration(sleepMs) * time.Millisecond)
+
+	for {
+		if itemID != "" && isDownloadCancelled(itemID) {
+			return r.vm.ToValue(false)
+		}
+
+		remaining := time.Until(deadline)
+		if remaining <= 0 {
+			return r.vm.ToValue(true)
+		}
+
+		step := 100 * time.Millisecond
+		if remaining < step {
+			step = remaining
+		}
+		time.Sleep(step)
+	}
+}
+
+func (r *extensionRuntime) isDownloadCancelled(call goja.FunctionCall) goja.Value {
+	itemID := r.getActiveDownloadItemID()
+	if itemID == "" {
+		return r.vm.ToValue(false)
+	}
+	return r.vm.ToValue(isDownloadCancelled(itemID))
+}
+
+func (r *extensionRuntime) logDebug(call goja.FunctionCall) goja.Value {
 	msg := r.formatLogArgs(call.Arguments)
 	GoLog("[Extension:%s:DEBUG] %s\n", r.extensionID, msg)
 	return goja.Undefined()
 }
 
-func (r *ExtensionRuntime) logInfo(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) logInfo(call goja.FunctionCall) goja.Value {
 	msg := r.formatLogArgs(call.Arguments)
 	GoLog("[Extension:%s:INFO] %s\n", r.extensionID, msg)
 	return goja.Undefined()
 }
 
-func (r *ExtensionRuntime) logWarn(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) logWarn(call goja.FunctionCall) goja.Value {
 	msg := r.formatLogArgs(call.Arguments)
 	GoLog("[Extension:%s:WARN] %s\n", r.extensionID, msg)
 	return goja.Undefined()
 }
 
-func (r *ExtensionRuntime) logError(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) logError(call goja.FunctionCall) goja.Value {
 	msg := r.formatLogArgs(call.Arguments)
 	GoLog("[Extension:%s:ERROR] %s\n", r.extensionID, msg)
 	return goja.Undefined()
 }
 
-func (r *ExtensionRuntime) formatLogArgs(args []goja.Value) string {
+func (r *extensionRuntime) formatLogArgs(args []goja.Value) string {
 	parts := make([]string, len(args))
 	for i, arg := range args {
 		parts[i] = fmt.Sprintf("%v", arg.Export())
@@ -281,7 +344,7 @@ func (r *ExtensionRuntime) formatLogArgs(args []goja.Value) string {
 	return strings.Join(parts, " ")
 }
 
-func (r *ExtensionRuntime) sanitizeFilenameWrapper(call goja.FunctionCall) goja.Value {
+func (r *extensionRuntime) sanitizeFilenameWrapper(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
 	}
@@ -289,7 +352,7 @@ func (r *ExtensionRuntime) sanitizeFilenameWrapper(call goja.FunctionCall) goja.
 	return r.vm.ToValue(sanitizeFilename(input))
 }
 
-func (r *ExtensionRuntime) RegisterGoBackendAPIs(vm *goja.Runtime) {
+func (r *extensionRuntime) RegisterGoBackendAPIs(vm *goja.Runtime) {
 	gobackendObj := vm.Get("gobackend")
 	if gobackendObj == nil || goja.IsUndefined(gobackendObj) {
 		gobackendObj = vm.NewObject()

go_backend/extension_store.go

@@ -26,7 +26,6 @@ type storeExtension struct {
 	Name             string   `json:"name"`
 	DisplayName      string   `json:"display_name,omitempty"`
 	Version          string   `json:"version"`
-	Author           string   `json:"author"`
 	Description      string   `json:"description"`
 	DownloadURL      string   `json:"download_url,omitempty"`
 	IconURL          string   `json:"icon_url,omitempty"`
@@ -83,7 +82,6 @@ type storeExtensionResponse struct {
 	Name             string   `json:"name"`
 	DisplayName      string   `json:"display_name"`
 	Version          string   `json:"version"`
-	Author           string   `json:"author"`
 	Description      string   `json:"description"`
 	DownloadURL      string   `json:"download_url"`
 	IconURL          string   `json:"icon_url,omitempty"`
@@ -103,7 +101,6 @@ func (e *storeExtension) toResponse() storeExtensionResponse {
 		Name:          e.Name,
 		DisplayName:   e.getDisplayName(),
 		Version:       e.Version,
-		Author:        e.Author,
 		Description:   e.Description,
 		DownloadURL:   e.getDownloadURL(),
 		IconURL:       e.getIconURL(),
@@ -253,7 +250,17 @@ func (s *extensionStore) fetchRegistry(forceRefresh bool) (*storeRegistry, error
 	LogInfo("ExtensionStore", "Fetching registry from %s", s.registryURL)
 
 	client := NewHTTPClientWithTimeout(30 * time.Second)
-	resp, err := client.Get(s.registryURL)
+	req, err := http.NewRequest(http.MethodGet, s.registryURL, nil)
+	if err != nil {
+		if s.cache != nil {
+			LogWarn("ExtensionStore", "Failed to build registry request, using cached registry: %v", err)
+			return s.cache, nil
+		}
+		return nil, fmt.Errorf("failed to build registry request: %w", err)
+	}
+	req.Header.Set("Cache-Control", "no-cache")
+	req.Header.Set("Pragma", "no-cache")
+	resp, err := client.Do(req)
 	if err != nil {
 		if s.cache != nil {
 			LogWarn("ExtensionStore", "Network error, using cached registry: %v", err)
@@ -295,7 +302,7 @@ func (s *extensionStore) getExtensionsWithStatus(forceRefresh bool) ([]storeExte
 		return nil, err
 	}
 
-	manager := GetExtensionManager()
+	manager := getExtensionManager()
 	installed := make(map[string]string) // id -> version
 
 	if manager != nil {
@@ -348,7 +355,13 @@ func (s *extensionStore) downloadExtension(extensionID string, destPath string)
 	LogInfo("ExtensionStore", "Downloading %s from %s", ext.getDisplayName(), ext.getDownloadURL())
 
 	client := NewHTTPClientWithTimeout(5 * time.Minute)
-	resp, err := client.Get(ext.getDownloadURL())
+	req, err := http.NewRequest(http.MethodGet, ext.getDownloadURL(), nil)
+	if err != nil {
+		return fmt.Errorf("failed to build download request: %w", err)
+	}
+	req.Header.Set("Cache-Control", "no-cache")
+	req.Header.Set("Pragma", "no-cache")
+	resp, err := client.Do(req)
 	if err != nil {
 		return fmt.Errorf("failed to download: %w", err)
 	}
@@ -481,8 +494,7 @@ func (s *extensionStore) searchExtensions(query string, category string) ([]stor
 		if query != "" {
 			if !containsIgnoreCase(ext.Name, queryLower) &&
 				!containsIgnoreCase(ext.DisplayName, queryLower) &&
-				!containsIgnoreCase(ext.Description, queryLower) &&
-				!containsIgnoreCase(ext.Author, queryLower) {
+				!containsIgnoreCase(ext.Description, queryLower) {
 				found := false
 				for _, tag := range ext.Tags {
 					if containsIgnoreCase(tag, queryLower) {

go_backend/extension_test.go

@@ -1,8 +1,10 @@
 package gobackend
 
 import (
+	"net/http"
 	"path/filepath"
 	"testing"
+	"time"
 
 	"github.com/dop251/goja"
 )
@@ -12,7 +14,6 @@ func TestParseManifest_Valid(t *testing.T) {
 		"name": "test-provider",
 		"displayName": "Test Provider",
 		"version": "1.0.0",
-		"author": "Test Author",
 		"description": "A test extension",
 		"type": ["metadata_provider"],
 		"permissions": {
@@ -46,7 +47,6 @@ func TestParseManifest_Valid(t *testing.T) {
 func TestParseManifest_MissingName(t *testing.T) {
 	invalidManifest := `{
 		"version": "1.0.0",
-		"author": "Test Author",
 		"description": "A test extension",
 		"type": ["metadata_provider"]
 	}`
@@ -61,7 +61,6 @@ func TestParseManifest_MissingType(t *testing.T) {
 	invalidManifest := `{
 		"name": "test-provider",
 		"version": "1.0.0",
-		"author": "Test Author",
 		"description": "A test extension"
 	}`
 
@@ -99,7 +98,7 @@ func TestIsDomainAllowed(t *testing.T) {
 
 func TestExtensionRuntime_NetworkSandbox(t *testing.T) {
 	// Create a mock extension with limited network permissions
-	ext := &LoadedExtension{
+	ext := &loadedExtension{
 		ID: "test-ext",
 		Manifest: &ExtensionManifest{
 			Name: "test-ext",
@@ -110,7 +109,7 @@ func TestExtensionRuntime_NetworkSandbox(t *testing.T) {
 		DataDir: t.TempDir(),
 	}
 
-	runtime := NewExtensionRuntime(ext)
+	runtime := newExtensionRuntime(ext)
 
 	if err := runtime.validateDomain("https://api.allowed.com/path"); err != nil {
 		t.Errorf("Expected api.allowed.com to be allowed, got error: %v", err)
@@ -132,7 +131,7 @@ func TestExtensionRuntime_NetworkSandbox(t *testing.T) {
 func TestExtensionRuntime_FileSandbox(t *testing.T) {
 	tempDir := t.TempDir()
 
-	ext := &LoadedExtension{
+	ext := &loadedExtension{
 		ID: "test-ext",
 		Manifest: &ExtensionManifest{
 			Name: "test-ext",
@@ -143,7 +142,7 @@ func TestExtensionRuntime_FileSandbox(t *testing.T) {
 		DataDir: tempDir,
 	}
 
-	runtime := NewExtensionRuntime(ext)
+	runtime := newExtensionRuntime(ext)
 
 	validPath, err := runtime.validatePath("test.txt")
 	if err != nil {
@@ -177,7 +176,7 @@ func TestExtensionRuntime_FileSandbox(t *testing.T) {
 		t.Error("Expected absolute path to be blocked")
 	}
 
-	extNoFile := &LoadedExtension{
+	extNoFile := &loadedExtension{
 		ID: "test-ext-no-file",
 		Manifest: &ExtensionManifest{
 			Name: "test-ext-no-file",
@@ -187,7 +186,7 @@ func TestExtensionRuntime_FileSandbox(t *testing.T) {
 		},
 		DataDir: tempDir,
 	}
-	runtimeNoFile := NewExtensionRuntime(extNoFile)
+	runtimeNoFile := newExtensionRuntime(extNoFile)
 	_, err = runtimeNoFile.validatePath("test.txt")
 	if err == nil {
 		t.Error("Expected file access to be denied without file permission")
@@ -195,7 +194,7 @@ func TestExtensionRuntime_FileSandbox(t *testing.T) {
 }
 
 func TestExtensionRuntime_UtilityFunctions(t *testing.T) {
-	ext := &LoadedExtension{
+	ext := &loadedExtension{
 		ID: "test-ext",
 		Manifest: &ExtensionManifest{
 			Name: "test-ext",
@@ -203,7 +202,7 @@ func TestExtensionRuntime_UtilityFunctions(t *testing.T) {
 		DataDir: t.TempDir(),
 	}
 
-	runtime := NewExtensionRuntime(ext)
+	runtime := newExtensionRuntime(ext)
 	vm := goja.New()
 	runtime.RegisterAPIs(vm)
 
@@ -239,11 +238,133 @@ func TestExtensionRuntime_UtilityFunctions(t *testing.T) {
 	if result.String() == "" {
 		t.Error("Expected non-empty JSON string")
 	}
+
+	result, err = vm.RunString(`utils.sleep(1)`)
+	if err != nil {
+		t.Fatalf("sleep failed: %v", err)
+	}
+	if !result.ToBoolean() {
+		t.Error("Expected sleep to complete successfully")
+	}
+
+	runtime.setActiveDownloadItemID("test-item")
+	cancelDownload("test-item")
+	t.Cleanup(func() {
+		clearDownloadCancel("test-item")
+		runtime.clearActiveDownloadItemID()
+	})
+
+	result, err = vm.RunString(`utils.isDownloadCancelled()`)
+	if err != nil {
+		t.Fatalf("isDownloadCancelled failed: %v", err)
+	}
+	if !result.ToBoolean() {
+		t.Error("Expected active download cancellation to be visible to JS")
+	}
+
+	SetAppVersion("4.2.2")
+	t.Cleanup(func() {
+		SetAppVersion("")
+	})
+
+	result, err = vm.RunString(`utils.appVersion()`)
+	if err != nil {
+		t.Fatalf("appVersion failed: %v", err)
+	}
+	if got := result.String(); got != "4.2.2" {
+		t.Fatalf("Expected appVersion 4.2.2, got %q", got)
+	}
+
+	result, err = vm.RunString(`utils.appUserAgent()`)
+	if err != nil {
+		t.Fatalf("appUserAgent failed: %v", err)
+	}
+	if got := result.String(); got != "SpotiFLAC-Mobile/4.2.2" {
+		t.Fatalf("Expected appUserAgent SpotiFLAC-Mobile/4.2.2, got %q", got)
+	}
+
+	result, err = vm.RunString(`utils.sleep(50)`)
+	if err != nil {
+		t.Fatalf("cancel-aware sleep failed: %v", err)
+	}
+	if result.ToBoolean() {
+		t.Error("Expected sleep to abort when download is cancelled")
+	}
+}
+
+func TestExtensionRuntime_BindDownloadCancelContext(t *testing.T) {
+	ext := &loadedExtension{
+		ID: "test-ext",
+		Manifest: &ExtensionManifest{
+			Name: "test-ext",
+		},
+		DataDir: t.TempDir(),
+	}
+
+	runtime := newExtensionRuntime(ext)
+	runtime.setActiveDownloadItemID("test-item")
+	t.Cleanup(func() {
+		clearDownloadCancel("test-item")
+		runtime.clearActiveDownloadItemID()
+	})
+
+	req, err := http.NewRequest("GET", "https://api.example.com/test", nil)
+	if err != nil {
+		t.Fatalf("NewRequest failed: %v", err)
+	}
+
+	req = runtime.bindDownloadCancelContext(req)
+	cancelDownload("test-item")
+
+	select {
+	case <-req.Context().Done():
+	case <-time.After(500 * time.Millisecond):
+		t.Fatal("Expected bound request context to be cancelled")
+	}
+
+	if req.Context().Err() == nil {
+		t.Fatal("Expected request context error after cancellation")
+	}
+}
+
+func TestExtensionRuntime_BindDownloadCancelContextPreservesPreCancelledState(t *testing.T) {
+	ext := &loadedExtension{
+		ID: "test-ext",
+		Manifest: &ExtensionManifest{
+			Name: "test-ext",
+		},
+		DataDir: t.TempDir(),
+	}
+
+	runtime := newExtensionRuntime(ext)
+	runtime.setActiveDownloadItemID("test-item")
+	cancelDownload("test-item")
+	t.Cleanup(func() {
+		clearDownloadCancel("test-item")
+		runtime.clearActiveDownloadItemID()
+	})
+
+	req, err := http.NewRequest("GET", "https://api.example.com/test", nil)
+	if err != nil {
+		t.Fatalf("NewRequest failed: %v", err)
+	}
+
+	req = runtime.bindDownloadCancelContext(req)
+
+	select {
+	case <-req.Context().Done():
+	case <-time.After(500 * time.Millisecond):
+		t.Fatal("Expected pre-cancelled request context to stay cancelled")
+	}
+
+	if req.Context().Err() == nil {
+		t.Fatal("Expected request context error for pre-cancelled item")
+	}
 }
 
 func TestExtensionRuntime_SSRFProtection(t *testing.T) {
 	// Create extension with limited network permissions
-	ext := &LoadedExtension{
+	ext := &loadedExtension{
 		ID: "test-ext",
 		Manifest: &ExtensionManifest{
 			Name: "test-ext",
@@ -254,7 +375,7 @@ func TestExtensionRuntime_SSRFProtection(t *testing.T) {
 		DataDir: t.TempDir(),
 	}
 
-	runtime := NewExtensionRuntime(ext)
+	runtime := newExtensionRuntime(ext)
 
 	privateIPs := []string{
 		"http://localhost/admin",

go_backend/extension_timeout.go

@@ -53,7 +53,7 @@ func RunWithTimeout(vm *goja.Runtime, script string, timeout time.Duration) (goj
 						IsTimeout: true,
 					}}
 				} else {
-					GoLog("[ExtensionRuntime] panic during JS execution: %v\n%s\n", r, string(debug.Stack()))
+					GoLog("[extensionRuntime] panic during JS execution: %v\n%s\n", r, string(debug.Stack()))
 					resultCh <- result{nil, fmt.Errorf("panic during execution: %v", r)}
 				}
 			}
@@ -90,7 +90,7 @@ func RunWithTimeout(vm *goja.Runtime, script string, timeout time.Duration) (goj
 		case <-time.After(60 * time.Second):
 			// Goroutine is truly stuck (e.g. HTTP read with no timeout).
 			// Log a warning — the VM should NOT be reused after this.
-			GoLog("[ExtensionRuntime] WARNING: JS goroutine did not exit within 60s after interrupt, VM may be unsafe\n")
+			GoLog("[extensionRuntime] WARNING: JS goroutine did not exit within 60s after interrupt, VM may be unsafe\n")
 			return nil, &JSExecutionError{
 				Message:   "execution timeout exceeded (force)",
 				IsTimeout: true,

go_backend/filename.go

@@ -6,6 +6,8 @@ import (
 	"strconv"
 	"strings"
 	"time"
+	"unicode"
+	"unicode/utf8"
 )
 
 var (
@@ -17,19 +19,42 @@ var (
 )
 
 func sanitizeFilename(filename string) string {
-	sanitized := invalidChars.ReplaceAllString(filename, "_")
+	sanitized := strings.ReplaceAll(filename, "/", " ")
+	sanitized = invalidChars.ReplaceAllString(sanitized, " ")
 
+	var builder strings.Builder
+	for _, r := range sanitized {
+		if r < 0x20 && r != 0x09 && r != 0x0A && r != 0x0D {
+			continue
+		}
+		if r == 0x7F {
+			continue
+		}
+		if unicode.IsControl(r) && r != 0x09 && r != 0x0A && r != 0x0D {
+			continue
+		}
+		builder.WriteRune(r)
+	}
+
+	sanitized = builder.String()
 	sanitized = strings.TrimSpace(sanitized)
-	sanitized = strings.Trim(sanitized, ".")
-
+	sanitized = strings.Trim(sanitized, ". ")
+	sanitized = strings.Join(strings.Fields(sanitized), " ")
 	sanitized = multiUnderscore.ReplaceAllString(sanitized, "_")
+	sanitized = strings.Trim(sanitized, "_ ")
+
+	if !utf8.ValidString(sanitized) {
+		sanitized = strings.ToValidUTF8(sanitized, "_")
+	}
 
 	if len(sanitized) > 200 {
 		sanitized = sanitized[:200]
+		sanitized = strings.TrimSpace(strings.Trim(sanitized, ". "))
+		sanitized = strings.Trim(sanitized, "_ ")
 	}
 
 	if sanitized == "" {
-		sanitized = "untitled"
+		return "Unknown"
 	}
 
 	return sanitized

go_backend/filename_test.go

@@ -83,3 +83,18 @@ func TestBuildFilenameFromTemplate_DateStrftimeFormattingWithYearOnly(t *testing
 		t.Fatalf("expected %q, got %q", expected, formatted)
 	}
 }
+
+func TestSanitizeFilenameMatchesDesktopSpacingBehavior(t *testing.T) {
+	got := sanitizeFilename(`  "Text In Quotes"?%* / Demo  `)
+	want := "Text In Quotes % Demo"
+	if got != want {
+		t.Fatalf("expected %q, got %q", want, got)
+	}
+}
+
+func TestSanitizeFilenameFallsBackToUnknownWhenEmpty(t *testing.T) {
+	got := sanitizeFilename(`<>:"/\|?*`)
+	if got != "Unknown" {
+		t.Fatalf("expected %q, got %q", "Unknown", got)
+	}
+}

go_backend/httputil.go

@@ -16,6 +16,19 @@ import (
 	"time"
 )
 
+func userAgentForURL(u *url.URL) string {
+	if u == nil {
+		return getRandomUserAgent()
+	}
+
+	host := strings.ToLower(strings.TrimSpace(u.Hostname()))
+	if host == "api.zarz.moe" {
+		return appUserAgent()
+	}
+
+	return getRandomUserAgent()
+}
+
 func getRandomUserAgent() string {
 	chromeVersion := rand.Intn(26) + 120
 	chromeBuild := rand.Intn(1500) + 6000
@@ -225,7 +238,7 @@ func cloneRequestWithHTTPScheme(req *http.Request, scheme string) (*http.Request
 }
 
 func DoRequestWithUserAgent(client *http.Client, req *http.Request) (*http.Response, error) {
-	req.Header.Set("User-Agent", getRandomUserAgent())
+	req.Header.Set("User-Agent", userAgentForURL(req.URL))
 	resp, err := client.Do(req)
 	if err != nil {
 		CheckAndLogISPBlocking(err, req.URL.String(), "HTTP")
@@ -255,7 +268,7 @@ func DoRequestWithRetry(client *http.Client, req *http.Request, config RetryConf
 
 	for attempt := 0; attempt <= config.MaxRetries; attempt++ {
 		reqCopy := req.Clone(req.Context())
-		reqCopy.Header.Set("User-Agent", getRandomUserAgent())
+		reqCopy.Header.Set("User-Agent", userAgentForURL(reqCopy.URL))
 
 		resp, err := client.Do(reqCopy)
 		if err != nil {

go_backend/httputil_ios.go

@@ -11,7 +11,7 @@ func GetCloudflareBypassClient() *http.Client {
 }
 
 func DoRequestWithCloudflareBypass(req *http.Request) (*http.Response, error) {
-	req.Header.Set("User-Agent", getRandomUserAgent())
+	req.Header.Set("User-Agent", userAgentForURL(req.URL))
 	resp, err := sharedClient.Do(req)
 	if err != nil {
 		CheckAndLogISPBlocking(err, req.URL.String(), "HTTP")

go_backend/httputil_utls.go

@@ -101,7 +101,7 @@ func GetCloudflareBypassClient() *http.Client {
 }
 
 func DoRequestWithCloudflareBypass(req *http.Request) (*http.Response, error) {
-	req.Header.Set("User-Agent", getRandomUserAgent())
+	req.Header.Set("User-Agent", userAgentForURL(req.URL))
 
 	resp, err := sharedClient.Do(req)
 	if err == nil {
@@ -129,7 +129,7 @@ func DoRequestWithCloudflareBypass(req *http.Request) (*http.Response, error) {
 					LogDebug("HTTP", "Cloudflare detected, retrying with Chrome TLS fingerprint...")
 
 					reqCopy := req.Clone(req.Context())
-					reqCopy.Header.Set("User-Agent", getRandomUserAgent())
+					reqCopy.Header.Set("User-Agent", userAgentForURL(reqCopy.URL))
 
 					return cloudflareBypassClient.Do(reqCopy)
 				}
@@ -155,7 +155,7 @@ func DoRequestWithCloudflareBypass(req *http.Request) (*http.Response, error) {
 		LogDebug("HTTP", "TLS error detected, retrying with Chrome TLS fingerprint: %v", err)
 
 		reqCopy := req.Clone(req.Context())
-		reqCopy.Header.Set("User-Agent", getRandomUserAgent())
+		reqCopy.Header.Set("User-Agent", userAgentForURL(reqCopy.URL))
 
 		return cloudflareBypassClient.Do(reqCopy)
 	}

go_backend/library_scan.go

@@ -24,13 +24,18 @@ type LibraryScanResult struct {
 	FileModTime          int64  `json:"fileModTime,omitempty"` // Unix timestamp in milliseconds
 	ISRC                 string `json:"isrc,omitempty"`
 	TrackNumber          int    `json:"trackNumber,omitempty"`
+	TotalTracks          int    `json:"totalTracks,omitempty"`
 	DiscNumber           int    `json:"discNumber,omitempty"`
+	TotalDiscs           int    `json:"totalDiscs,omitempty"`
 	Duration             int    `json:"duration,omitempty"`
 	ReleaseDate          string `json:"releaseDate,omitempty"`
 	BitDepth             int    `json:"bitDepth,omitempty"`
 	SampleRate           int    `json:"sampleRate,omitempty"`
 	Bitrate              int    `json:"bitrate,omitempty"` // kbps, for lossy formats (MP3, Opus, Vorbis)
 	Genre                string `json:"genre,omitempty"`
+	Composer             string `json:"composer,omitempty"`
+	Label                string `json:"label,omitempty"`
+	Copyright            string `json:"copyright,omitempty"`
 	Format               string `json:"format,omitempty"`
 	MetadataFromFilename bool   `json:"metadataFromFilename,omitempty"`
 }
@@ -365,9 +370,14 @@ func scanFLACFile(filePath string, result *LibraryScanResult, displayNameHint st
 	result.AlbumArtist = metadata.AlbumArtist
 	result.ISRC = metadata.ISRC
 	result.TrackNumber = metadata.TrackNumber
+	result.TotalTracks = metadata.TotalTracks
 	result.DiscNumber = metadata.DiscNumber
+	result.TotalDiscs = metadata.TotalDiscs
 	result.ReleaseDate = metadata.Date
 	result.Genre = metadata.Genre
+	result.Composer = metadata.Composer
+	result.Label = metadata.Label
+	result.Copyright = metadata.Copyright
 
 	quality, err := GetAudioQuality(filePath)
 	if err == nil {
@@ -397,12 +407,17 @@ func scanM4AFile(filePath string, result *LibraryScanResult, displayNameHint str
 		result.AlbumArtist = metadata.AlbumArtist
 		result.ISRC = metadata.ISRC
 		result.TrackNumber = metadata.TrackNumber
+		result.TotalTracks = metadata.TotalTracks
 		result.DiscNumber = metadata.DiscNumber
+		result.TotalDiscs = metadata.TotalDiscs
 		result.ReleaseDate = metadata.Date
 		if result.ReleaseDate == "" {
 			result.ReleaseDate = metadata.Year
 		}
 		result.Genre = metadata.Genre
+		result.Composer = metadata.Composer
+		result.Label = metadata.Label
+		result.Copyright = metadata.Copyright
 	}
 
 	quality, err := GetM4AQuality(filePath)
@@ -427,7 +442,9 @@ func scanMP3File(filePath string, result *LibraryScanResult, displayNameHint str
 	result.AlbumName = metadata.Album
 	result.AlbumArtist = metadata.AlbumArtist
 	result.TrackNumber = metadata.TrackNumber
+	result.TotalTracks = metadata.TotalTracks
 	result.DiscNumber = metadata.DiscNumber
+	result.TotalDiscs = metadata.TotalDiscs
 	result.Genre = metadata.Genre
 	if metadata.Date != "" {
 		result.ReleaseDate = metadata.Date
@@ -435,6 +452,9 @@ func scanMP3File(filePath string, result *LibraryScanResult, displayNameHint str
 		result.ReleaseDate = metadata.Year
 	}
 	result.ISRC = metadata.ISRC
+	result.Composer = metadata.Composer
+	result.Label = metadata.Label
+	result.Copyright = metadata.Copyright
 
 	quality, err := GetMP3Quality(filePath)
 	if err == nil {
@@ -464,9 +484,14 @@ func scanOggFile(filePath string, result *LibraryScanResult, displayNameHint str
 	result.AlbumArtist = metadata.AlbumArtist
 	result.ISRC = metadata.ISRC
 	result.TrackNumber = metadata.TrackNumber
+	result.TotalTracks = metadata.TotalTracks
 	result.DiscNumber = metadata.DiscNumber
+	result.TotalDiscs = metadata.TotalDiscs
 	result.Genre = metadata.Genre
 	result.ReleaseDate = metadata.Date
+	result.Composer = metadata.Composer
+	result.Label = metadata.Label
+	result.Copyright = metadata.Copyright
 
 	quality, err := GetOggQuality(filePath)
 	if err == nil {
@@ -501,13 +526,18 @@ func scanAPEFile(filePath string, result *LibraryScanResult, displayNameHint str
 	result.AlbumArtist = metadata.AlbumArtist
 	result.ISRC = metadata.ISRC
 	result.TrackNumber = metadata.TrackNumber
+	result.TotalTracks = metadata.TotalTracks
 	result.DiscNumber = metadata.DiscNumber
+	result.TotalDiscs = metadata.TotalDiscs
 	result.Genre = metadata.Genre
 	if metadata.Date != "" {
 		result.ReleaseDate = metadata.Date
 	} else {
 		result.ReleaseDate = metadata.Year
 	}
+	result.Composer = metadata.Composer
+	result.Label = metadata.Label
+	result.Copyright = metadata.Copyright
 
 	applyDefaultLibraryMetadata(filePath, displayNameHint, result)
 

go_backend/lyrics.go

@@ -39,8 +39,34 @@ var DefaultLyricsProviders = []string{
 var (
 	lyricsProvidersMu sync.RWMutex
 	lyricsProviders   []string // ordered list of enabled providers
+	appVersionMu      sync.RWMutex
+	appVersion        string
 )
 
+func SetAppVersion(version string) {
+	normalized := strings.TrimSpace(version)
+
+	appVersionMu.Lock()
+	defer appVersionMu.Unlock()
+	appVersion = normalized
+}
+
+func GetAppVersion() string {
+	appVersionMu.RLock()
+	defer appVersionMu.RUnlock()
+	return appVersion
+}
+
+func appUserAgent() string {
+	version := GetAppVersion()
+
+	if version == "" {
+		return "SpotiFLAC-Mobile"
+	}
+
+	return "SpotiFLAC-Mobile/" + version
+}
+
 type LyricsFetchOptions struct {
 	IncludeTranslationNetease  bool   `json:"include_translation_netease"`
 	IncludeRomanizationNetease bool   `json:"include_romanization_netease"`
@@ -385,8 +411,8 @@ func (c *LyricsClient) FetchLyricsAllSources(spotifyID, trackName, artistName st
 	primaryArtist := normalizeArtistName(artistName)
 	fetchOptions := GetLyricsFetchOptions()
 
-	extManager := GetExtensionManager()
-	var extensionProviders []*ExtensionProviderWrapper
+	extManager := getExtensionManager()
+	var extensionProviders []*extensionProviderWrapper
 	if extManager != nil {
 		extensionProviders = extManager.GetLyricsProviders()
 	}

go_backend/lyrics_apple.go

@@ -114,7 +114,7 @@ func (c *AppleMusicClient) SearchSong(trackName, artistName string, durationSec
 		return "", fmt.Errorf("failed to create request: %w", err)
 	}
 
-	req.Header.Set("User-Agent", getRandomUserAgent())
+	req.Header.Set("User-Agent", appUserAgent())
 	req.Header.Set("Accept", "application/json")
 
 	resp, err := c.httpClient.Do(req)
@@ -147,7 +147,8 @@ func (c *AppleMusicClient) FetchLyricsByID(songID string) (string, error) {
 	if err != nil {
 		return "", fmt.Errorf("failed to create request: %w", err)
 	}
-	req.Header.Set("User-Agent", getRandomUserAgent())
+	req.Header.Set("User-Agent", appUserAgent())
+	req.Header.Set("Accept", "application/json")
 
 	resp, err := c.httpClient.Do(req)
 	if err != nil {

go_backend/lyrics_musixmatch.go

@@ -72,7 +72,7 @@ func (c *MusixmatchClient) fetchLyricsPayload(trackName, artistName string, dura
 		return "", fmt.Errorf("failed to create request: %w", err)
 	}
 	req.Header.Set("Accept", "application/json")
-	req.Header.Set("User-Agent", getRandomUserAgent())
+	req.Header.Set("User-Agent", appUserAgent())
 
 	resp, err := c.httpClient.Do(req)
 	if err != nil {

go_backend/lyrics_netease.go

@@ -70,7 +70,7 @@ func (c *NeteaseClient) SearchSong(trackName, artistName string) (int64, error)
 	for k, v := range neteaseHeaders {
 		req.Header.Set(k, v)
 	}
-	req.Header.Set("User-Agent", getRandomUserAgent())
+	req.Header.Set("User-Agent", appUserAgent())
 
 	resp, err := c.httpClient.Do(req)
 	if err != nil {
@@ -109,7 +109,7 @@ func (c *NeteaseClient) FetchLyricsByID(songID int64, includeTranslation, includ
 	for k, v := range neteaseHeaders {
 		req.Header.Set(k, v)
 	}
-	req.Header.Set("User-Agent", getRandomUserAgent())
+	req.Header.Set("User-Agent", appUserAgent())
 
 	resp, err := c.httpClient.Do(req)
 	if err != nil {

go_backend/lyrics_qqmusic.go

@@ -54,7 +54,7 @@ func (c *QQMusicClient) fetchLyricsByMetadata(trackName, artistName string, dura
 	}
 	req.Header.Set("Content-Type", "application/json")
 	req.Header.Set("Accept", "application/json")
-	req.Header.Set("User-Agent", getRandomUserAgent())
+	req.Header.Set("User-Agent", appUserAgent())
 
 	resp, err := c.httpClient.Do(req)
 	if err != nil {

go_backend/metadata.go

@@ -9,6 +9,7 @@ import (
 	_ "image/jpeg"
 	_ "image/png"
 	"io"
+	"math"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -110,6 +111,7 @@ type Metadata struct {
 	TrackNumber   int
 	TotalTracks   int
 	DiscNumber    int
+	TotalDiscs    int
 	ISRC          string
 	Description   string
 	Lyrics        string
@@ -273,23 +275,23 @@ func ReadMetadata(filePath string) (*Metadata, error) {
 
 			trackNum := getComment(cmt, "TRACKNUMBER")
 			if trackNum != "" {
-				fmt.Sscanf(trackNum, "%d", &metadata.TrackNumber)
+				metadata.TrackNumber, metadata.TotalTracks = parseIndexPair(trackNum)
 			}
 			if metadata.TrackNumber == 0 {
 				trackNum = getComment(cmt, "TRACK")
 				if trackNum != "" {
-					fmt.Sscanf(trackNum, "%d", &metadata.TrackNumber)
+					metadata.TrackNumber, metadata.TotalTracks = parseIndexPair(trackNum)
 				}
 			}
 
 			discNum := getComment(cmt, "DISCNUMBER")
 			if discNum != "" {
-				fmt.Sscanf(discNum, "%d", &metadata.DiscNumber)
+				metadata.DiscNumber, metadata.TotalDiscs = parseIndexPair(discNum)
 			}
 			if metadata.DiscNumber == 0 {
 				discNum = getComment(cmt, "DISC")
 				if discNum != "" {
-					fmt.Sscanf(discNum, "%d", &metadata.DiscNumber)
+					metadata.DiscNumber, metadata.TotalDiscs = parseIndexPair(discNum)
 				}
 			}
 
@@ -403,26 +405,39 @@ func EditFlacFields(filePath string, fields map[string]string) error {
 		removeCommentKey(cmt, "ALBUM_ARTIST")
 	}
 
-	// Track/disc numbers: present + empty → clear; present + "0" → clear.
-	if v, ok := fields["track_number"]; ok {
-		trackNum := 0
-		if v != "" {
-			fmt.Sscanf(v, "%d", &trackNum)
+	// Track/disc numbers: present + empty → clear; when only totals are edited,
+	// preserve the current index number and rewrite the combined value.
+	if _, ok := fields["track_number"]; ok || fields["track_total"] != "" || hasMapKey(fields, "track_total") {
+		currentTrackNum, currentTotalTracks := parseIndexPair(getComment(cmt, "TRACKNUMBER"))
+		if currentTrackNum == 0 && currentTotalTracks == 0 {
+			currentTrackNum, currentTotalTracks = parseIndexPair(getComment(cmt, "TRACK"))
 		}
-		if trackNum > 0 {
-			setOrClearComment(cmt, "TRACKNUMBER", strconv.Itoa(trackNum))
+		if v, ok := fields["track_number"]; ok {
+			currentTrackNum = parsePositiveInt(v)
+		}
+		if v, ok := fields["track_total"]; ok {
+			currentTotalTracks = parsePositiveInt(v)
+		}
+		if currentTrackNum > 0 {
+			setOrClearComment(cmt, "TRACKNUMBER", formatIndexValue(currentTrackNum, currentTotalTracks))
 		} else {
 			removeCommentKey(cmt, "TRACKNUMBER")
 		}
 		removeCommentKey(cmt, "TRACK") // alias
 	}
-	if v, ok := fields["disc_number"]; ok {
-		discNum := 0
-		if v != "" {
-			fmt.Sscanf(v, "%d", &discNum)
+	if _, ok := fields["disc_number"]; ok || fields["disc_total"] != "" || hasMapKey(fields, "disc_total") {
+		currentDiscNum, currentTotalDiscs := parseIndexPair(getComment(cmt, "DISCNUMBER"))
+		if currentDiscNum == 0 && currentTotalDiscs == 0 {
+			currentDiscNum, currentTotalDiscs = parseIndexPair(getComment(cmt, "DISC"))
 		}
-		if discNum > 0 {
-			setOrClearComment(cmt, "DISCNUMBER", strconv.Itoa(discNum))
+		if v, ok := fields["disc_number"]; ok {
+			currentDiscNum = parsePositiveInt(v)
+		}
+		if v, ok := fields["disc_total"]; ok {
+			currentTotalDiscs = parsePositiveInt(v)
+		}
+		if currentDiscNum > 0 {
+			setOrClearComment(cmt, "DISCNUMBER", formatIndexValue(currentDiscNum, currentTotalDiscs))
 		} else {
 			removeCommentKey(cmt, "DISCNUMBER")
 		}
@@ -478,15 +493,11 @@ func writeVorbisMetadata(cmt *flacvorbis.MetaDataBlockVorbisComment, metadata Me
 	setComment(cmt, "DATE", metadata.Date)
 
 	if metadata.TrackNumber > 0 {
-		if metadata.TotalTracks > 0 {
-			setComment(cmt, "TRACKNUMBER", fmt.Sprintf("%d/%d", metadata.TrackNumber, metadata.TotalTracks))
-		} else {
-			setComment(cmt, "TRACKNUMBER", strconv.Itoa(metadata.TrackNumber))
-		}
+		setComment(cmt, "TRACKNUMBER", formatIndexValue(metadata.TrackNumber, metadata.TotalTracks))
 	}
 
 	if metadata.DiscNumber > 0 {
-		setComment(cmt, "DISCNUMBER", strconv.Itoa(metadata.DiscNumber))
+		setComment(cmt, "DISCNUMBER", formatIndexValue(metadata.DiscNumber, metadata.TotalDiscs))
 	}
 
 	if metadata.ISRC != "" {
@@ -953,9 +964,9 @@ func ReadM4ATags(filePath string) (*AudioMetadata, error) {
 		case "\xa9lyr":
 			metadata.Lyrics, _ = readM4ATextValue(f, header, fi.Size())
 		case "trkn":
-			metadata.TrackNumber, _ = readM4AIndexValue(f, header, fi.Size())
+			metadata.TrackNumber, metadata.TotalTracks, _ = readM4AIndexPair(f, header, fi.Size())
 		case "disk":
-			metadata.DiscNumber, _ = readM4AIndexValue(f, header, fi.Size())
+			metadata.DiscNumber, metadata.TotalDiscs, _ = readM4AIndexPair(f, header, fi.Size())
 		case "----":
 			name, value, freeformErr := readM4AFreeformValue(f, header, fi.Size())
 			if freeformErr == nil {
@@ -1150,6 +1161,41 @@ func readM4AIndexValue(f *os.File, parent atomHeader, fileSize int64) (int, erro
 	return int(binary.BigEndian.Uint16(payload[2:4])), nil
 }
 
+func readM4AIndexPair(f *os.File, parent atomHeader, fileSize int64) (int, int, error) {
+	payload, err := readM4ADataPayload(f, parent, fileSize)
+	if err != nil {
+		return 0, 0, err
+	}
+	if len(payload) < 6 {
+		return 0, 0, fmt.Errorf("index payload too short in %s", parent.typ)
+	}
+	return int(binary.BigEndian.Uint16(payload[2:4])), int(binary.BigEndian.Uint16(payload[4:6])), nil
+}
+
+func parsePositiveInt(value string) int {
+	value = strings.TrimSpace(value)
+	if value == "" {
+		return 0
+	}
+	n, _ := strconv.Atoi(value)
+	return n
+}
+
+func formatIndexValue(number, total int) string {
+	if number <= 0 {
+		return ""
+	}
+	if total > 0 {
+		return fmt.Sprintf("%d/%d", number, total)
+	}
+	return strconv.Itoa(number)
+}
+
+func hasMapKey(fields map[string]string, key string) bool {
+	_, ok := fields[key]
+	return ok
+}
+
 func readM4AFreeformValue(f *os.File, parent atomHeader, fileSize int64) (string, string, error) {
 	start := parent.offset + parent.headerSize
 	end := parent.offset + parent.size
@@ -1199,6 +1245,281 @@ func readM4AFreeformValue(f *os.File, parent atomHeader, fileSize int64) (string
 	return nameValue, dataValue, nil
 }
 
+type m4aMetadataPath struct {
+	moov atomHeader
+	udta *atomHeader
+	meta atomHeader
+	ilst atomHeader
+}
+
+func findM4AMetadataPath(f *os.File, fileSize int64) (m4aMetadataPath, error) {
+	moov, found, err := findAtomInRange(f, 0, fileSize, "moov", fileSize)
+	if err != nil || !found {
+		return m4aMetadataPath{}, fmt.Errorf("moov not found")
+	}
+
+	moovBodyStart := moov.offset + moov.headerSize
+	moovBodySize := moov.size - moov.headerSize
+
+	if udta, ok, _ := findAtomInRange(f, moovBodyStart, moovBodySize, "udta", fileSize); ok {
+		udtaBodyStart := udta.offset + udta.headerSize
+		udtaBodySize := udta.size - udta.headerSize
+		if meta, ok2, _ := findAtomInRange(f, udtaBodyStart, udtaBodySize, "meta", fileSize); ok2 {
+			metaBodyStart := meta.offset + meta.headerSize + 4
+			metaBodySize := meta.size - meta.headerSize - 4
+			if ilst, ok3, _ := findAtomInRange(f, metaBodyStart, metaBodySize, "ilst", fileSize); ok3 {
+				udtaCopy := udta
+				return m4aMetadataPath{
+					moov: moov,
+					udta: &udtaCopy,
+					meta: meta,
+					ilst: ilst,
+				}, nil
+			}
+		}
+	}
+
+	if meta, ok, _ := findAtomInRange(f, moovBodyStart, moovBodySize, "meta", fileSize); ok {
+		metaBodyStart := meta.offset + meta.headerSize + 4
+		metaBodySize := meta.size - meta.headerSize - 4
+		if ilst, ok2, _ := findAtomInRange(f, metaBodyStart, metaBodySize, "ilst", fileSize); ok2 {
+			return m4aMetadataPath{
+				moov: moov,
+				meta: meta,
+				ilst: ilst,
+			}, nil
+		}
+	}
+
+	return m4aMetadataPath{}, fmt.Errorf("ilst not found (tried moov>udta>meta>ilst and moov>meta>ilst)")
+}
+
+func buildM4AAtom(typ string, payload []byte) []byte {
+	size := int64(8 + len(payload))
+	buf := make([]byte, 8+len(payload))
+	binary.BigEndian.PutUint32(buf[0:4], uint32(size))
+	copy(buf[4:8], []byte(typ))
+	copy(buf[8:], payload)
+	return buf
+}
+
+func buildM4AFreeformAtom(name, value string) []byte {
+	meanPayload := append([]byte{0, 0, 0, 0}, []byte("com.apple.iTunes")...)
+	namePayload := append([]byte{0, 0, 0, 0}, []byte(name)...)
+	dataPayload := make([]byte, 8+len(value))
+	binary.BigEndian.PutUint32(dataPayload[0:4], 1) // UTF-8 text
+	copy(dataPayload[8:], []byte(value))
+
+	payload := append([]byte{}, buildM4AAtom("mean", meanPayload)...)
+	payload = append(payload, buildM4AAtom("name", namePayload)...)
+	payload = append(payload, buildM4AAtom("data", dataPayload)...)
+	return buildM4AAtom("----", payload)
+}
+
+func buildITunNORMTag(trackGain, trackPeak string) string {
+	gainDb, ok := parseReplayGainDb(trackGain)
+	if !ok {
+		return ""
+	}
+	peakLinear, ok := parseReplayGainPeak(trackPeak)
+	if !ok {
+		return ""
+	}
+
+	clamp := func(v int64) int64 {
+		if v < 0 {
+			return 0
+		}
+		if v > 65534 {
+			return 65534
+		}
+		return v
+	}
+
+	g1 := clamp(int64(math.Round(math.Pow(10, gainDb/-10.0) * 1000.0)))
+	g2 := clamp(int64(math.Round(math.Pow(10, gainDb/-10.0) * 2500.0)))
+	peak := clamp(int64(math.Round(peakLinear * 32768.0)))
+	values := []int64{g1, g1, g2, g2, 0, 0, peak, peak, 0, 0}
+	parts := make([]string, 0, len(values))
+	for _, value := range values {
+		parts = append(parts, strings.ToUpper(fmt.Sprintf("%08x", value)))
+	}
+	return strings.Join(parts, " ")
+}
+
+func parseReplayGainDb(value string) (float64, bool) {
+	match := regexp.MustCompile(`([+-]?\d+(?:\.\d+)?)`).FindStringSubmatch(strings.TrimSpace(value))
+	if len(match) < 2 {
+		return 0, false
+	}
+	parsed, err := strconv.ParseFloat(match[1], 64)
+	if err != nil {
+		return 0, false
+	}
+	return parsed, true
+}
+
+func parseReplayGainPeak(value string) (float64, bool) {
+	parsed, err := strconv.ParseFloat(strings.TrimSpace(value), 64)
+	if err != nil || parsed <= 0 {
+		return 0, false
+	}
+	return parsed, true
+}
+
+func collectM4AReplayGainFields(fields map[string]string) map[string]string {
+	result := map[string]string{}
+	if value := strings.TrimSpace(fields["replaygain_track_gain"]); value != "" {
+		result["replaygain_track_gain"] = value
+	}
+	if value := strings.TrimSpace(fields["replaygain_track_peak"]); value != "" {
+		result["replaygain_track_peak"] = value
+	}
+	if value := strings.TrimSpace(fields["replaygain_album_gain"]); value != "" {
+		result["replaygain_album_gain"] = value
+	}
+	if value := strings.TrimSpace(fields["replaygain_album_peak"]); value != "" {
+		result["replaygain_album_peak"] = value
+	}
+
+	if norm := buildITunNORMTag(result["replaygain_track_gain"], result["replaygain_track_peak"]); norm != "" {
+		result["iTunNORM"] = norm
+	}
+
+	return result
+}
+
+func writeAtomSize(buf []byte, header atomHeader, newSize int64) error {
+	if newSize <= 0 {
+		return fmt.Errorf("invalid size for %s", header.typ)
+	}
+	if header.headerSize == 16 {
+		if int(header.offset)+16 > len(buf) {
+			return io.ErrUnexpectedEOF
+		}
+		binary.BigEndian.PutUint32(buf[header.offset:header.offset+4], 1)
+		binary.BigEndian.PutUint64(buf[header.offset+8:header.offset+16], uint64(newSize))
+		return nil
+	}
+	if newSize > math.MaxUint32 {
+		return fmt.Errorf("atom %s too large for 32-bit header", header.typ)
+	}
+	if int(header.offset)+8 > len(buf) {
+		return io.ErrUnexpectedEOF
+	}
+	binary.BigEndian.PutUint32(buf[header.offset:header.offset+4], uint32(newSize))
+	return nil
+}
+
+func EditM4AReplayGain(filePath string, fields map[string]string) error {
+	replayGainFields := collectM4AReplayGainFields(fields)
+	if len(replayGainFields) == 0 {
+		return nil
+	}
+
+	f, err := os.Open(filePath)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	info, err := f.Stat()
+	if err != nil {
+		return err
+	}
+
+	path, err := findM4AMetadataPath(f, info.Size())
+	if err != nil {
+		return err
+	}
+
+	data, err := os.ReadFile(filePath)
+	if err != nil {
+		return err
+	}
+
+	bodyStart := path.ilst.offset + path.ilst.headerSize
+	bodyEnd := path.ilst.offset + path.ilst.size
+	newBody := make([]byte, 0, int(path.ilst.size))
+	targets := map[string]struct{}{
+		"REPLAYGAIN_TRACK_GAIN": {},
+		"REPLAYGAIN_TRACK_PEAK": {},
+		"REPLAYGAIN_ALBUM_GAIN": {},
+		"REPLAYGAIN_ALBUM_PEAK": {},
+		"ITUNNORM":              {},
+	}
+
+	for pos := bodyStart; pos+8 <= bodyEnd; {
+		header, readErr := readAtomHeaderAt(f, pos, info.Size())
+		if readErr != nil {
+			return readErr
+		}
+		if header.size == 0 {
+			header.size = bodyEnd - pos
+		}
+		if header.size < header.headerSize {
+			return fmt.Errorf("invalid atom size for %s", header.typ)
+		}
+
+		keep := true
+		if header.typ == "----" {
+			name, _, freeformErr := readM4AFreeformValue(f, header, info.Size())
+			if freeformErr == nil {
+				if _, ok := targets[strings.ToUpper(strings.TrimSpace(name))]; ok {
+					keep = false
+				}
+			}
+		}
+		if keep {
+			newBody = append(newBody, data[pos:pos+header.size]...)
+		}
+
+		pos += header.size
+	}
+
+	order := []string{
+		"replaygain_track_gain",
+		"replaygain_track_peak",
+		"replaygain_album_gain",
+		"replaygain_album_peak",
+		"iTunNORM",
+	}
+	for _, key := range order {
+		value := strings.TrimSpace(replayGainFields[key])
+		if value == "" {
+			continue
+		}
+		name := key
+		if key != "iTunNORM" {
+			name = strings.ToLower(key)
+		}
+		newBody = append(newBody, buildM4AFreeformAtom(name, value)...)
+	}
+
+	newIlst := buildM4AAtom("ilst", newBody)
+	updated := append([]byte{}, data[:path.ilst.offset]...)
+	updated = append(updated, newIlst...)
+	updated = append(updated, data[path.ilst.offset+path.ilst.size:]...)
+
+	delta := int64(len(newIlst)) - path.ilst.size
+	if err := writeAtomSize(updated, path.ilst, path.ilst.size+delta); err != nil {
+		return err
+	}
+	if err := writeAtomSize(updated, path.meta, path.meta.size+delta); err != nil {
+		return err
+	}
+	if path.udta != nil {
+		if err := writeAtomSize(updated, *path.udta, path.udta.size+delta); err != nil {
+			return err
+		}
+	}
+	if err := writeAtomSize(updated, path.moov, path.moov.size+delta); err != nil {
+		return err
+	}
+
+	return os.WriteFile(filePath, updated, 0o644)
+}
+
 func extractLyricsFromSidecarLRC(filePath string) (string, error) {
 	ext := filepath.Ext(filePath)
 	base := strings.TrimSuffix(filePath, ext)
@@ -1378,16 +1699,82 @@ func GetM4AQuality(filePath string) (AudioQuality, error) {
 	//   [28:32] samplerate (16.16 fixed-point)
 	sampleRate := int(buf[28])<<8 | int(buf[29])
 	bitDepth := int(buf[22])<<8 | int(buf[23])
-	if bitDepth <= 0 {
-		bitDepth = 16
-		if atomType == "alac" {
-			bitDepth = 24
+
+	if atomType == "alac" {
+		if alacBitDepth, alacSampleRate, ok := readALACSpecificConfig(f, sampleOffset, fileSize); ok {
+			if alacBitDepth > 0 {
+				bitDepth = alacBitDepth
+			}
+			if alacSampleRate > 0 {
+				sampleRate = alacSampleRate
+			}
 		}
 	}
 
+	if bitDepth <= 0 {
+		bitDepth = 16
+	}
+
 	return AudioQuality{BitDepth: bitDepth, SampleRate: sampleRate}, nil
 }
 
+func readALACSpecificConfig(f *os.File, sampleOffset, fileSize int64) (int, int, bool) {
+	if sampleOffset < 4 {
+		return 0, 0, false
+	}
+
+	sampleEntryHeader, err := readAtomHeaderAt(f, sampleOffset-4, fileSize)
+	if err != nil {
+		return 0, 0, false
+	}
+
+	childStart := sampleOffset + 32
+	childEnd := sampleEntryHeader.offset + sampleEntryHeader.size
+	if childStart >= childEnd {
+		return 0, 0, false
+	}
+
+	configHeader, found, err := findAtomInRange(f, childStart, childEnd-childStart, "alac", fileSize)
+	if err != nil || !found {
+		return 0, 0, false
+	}
+
+	payloadSize := configHeader.size - configHeader.headerSize
+	if payloadSize <= 0 {
+		return 0, 0, false
+	}
+
+	payload := make([]byte, payloadSize)
+	if _, err := f.ReadAt(payload, configHeader.offset+configHeader.headerSize); err != nil {
+		return 0, 0, false
+	}
+
+	return parseALACSpecificConfig(payload)
+}
+
+func parseALACSpecificConfig(payload []byte) (int, int, bool) {
+	if len(payload) < 24 {
+		return 0, 0, false
+	}
+
+	bitDepth := int(payload[5])
+	sampleRate := int(binary.BigEndian.Uint32(payload[20:24]))
+	if bitDepth > 0 && sampleRate > 0 {
+		return bitDepth, sampleRate, true
+	}
+
+	// Some encoders prepend 4 bytes before the ALACSpecificConfig payload.
+	if len(payload) >= 28 {
+		bitDepth = int(payload[9])
+		sampleRate = int(binary.BigEndian.Uint32(payload[24:28]))
+		if bitDepth > 0 && sampleRate > 0 {
+			return bitDepth, sampleRate, true
+		}
+	}
+
+	return 0, 0, false
+}
+
 type atomHeader struct {
 	offset     int64
 	size       int64

go_backend/metadata_m4a_quality_test.go

@@ -0,0 +1,49 @@
+package gobackend
+
+import "testing"
+
+func TestParseALACSpecificConfigStandardPayload(t *testing.T) {
+	payload := make([]byte, 24)
+	payload[5] = 24
+	payload[20] = 0x00
+	payload[21] = 0x00
+	payload[22] = 0xac
+	payload[23] = 0x44
+
+	bitDepth, sampleRate, ok := parseALACSpecificConfig(payload)
+	if !ok {
+		t.Fatal("expected standard ALAC payload to parse")
+	}
+	if bitDepth != 24 {
+		t.Fatalf("bitDepth = %d, want 24", bitDepth)
+	}
+	if sampleRate != 44100 {
+		t.Fatalf("sampleRate = %d, want 44100", sampleRate)
+	}
+}
+
+func TestParseALACSpecificConfigPayloadWithLeadingFourBytes(t *testing.T) {
+	payload := make([]byte, 28)
+	payload[9] = 16
+	payload[24] = 0x00
+	payload[25] = 0x00
+	payload[26] = 0xbb
+	payload[27] = 0x80
+
+	bitDepth, sampleRate, ok := parseALACSpecificConfig(payload)
+	if !ok {
+		t.Fatal("expected offset ALAC payload to parse")
+	}
+	if bitDepth != 16 {
+		t.Fatalf("bitDepth = %d, want 16", bitDepth)
+	}
+	if sampleRate != 48000 {
+		t.Fatalf("sampleRate = %d, want 48000", sampleRate)
+	}
+}
+
+func TestParseALACSpecificConfigRejectsShortPayload(t *testing.T) {
+	if _, _, ok := parseALACSpecificConfig(make([]byte, 12)); ok {
+		t.Fatal("expected short ALAC payload to be rejected")
+	}
+}

go_backend/metadata_types.go

@@ -23,11 +23,13 @@ type TrackMetadata struct {
 	TrackNumber int    `json:"track_number"`
 	TotalTracks int    `json:"total_tracks,omitempty"`
 	DiscNumber  int    `json:"disc_number,omitempty"`
+	TotalDiscs  int    `json:"total_discs,omitempty"`
 	ExternalURL string `json:"external_urls"`
 	ISRC        string `json:"isrc"`
 	AlbumID     string `json:"album_id,omitempty"`
 	ArtistID    string `json:"artist_id,omitempty"`
 	AlbumType   string `json:"album_type,omitempty"`
+	Composer    string `json:"composer,omitempty"`
 }
 
 type AlbumTrackMetadata struct {
@@ -42,11 +44,13 @@ type AlbumTrackMetadata struct {
 	TrackNumber int    `json:"track_number"`
 	TotalTracks int    `json:"total_tracks,omitempty"`
 	DiscNumber  int    `json:"disc_number,omitempty"`
+	TotalDiscs  int    `json:"total_discs,omitempty"`
 	ExternalURL string `json:"external_urls"`
 	ISRC        string `json:"isrc"`
 	AlbumID     string `json:"album_id,omitempty"`
 	AlbumURL    string `json:"album_url,omitempty"`
 	AlbumType   string `json:"album_type,omitempty"`
+	Composer    string `json:"composer,omitempty"`
 }
 
 type AlbumInfoMetadata struct {

go_backend/qobuz.go

@@ -55,6 +55,7 @@ const (
 	qobuzTrackPlayBaseURL   = "https://play.qobuz.com/track/"
 	qobuzStoreBaseURL       = "https://www.qobuz.com/us-en"
 	qobuzDownloadAPIURL     = "https://dl.musicdl.me/qobuz/download"
+	qobuzZarzDownloadAPIURL = "https://api.zarz.moe/dl/qbz"
 	qobuzDabMusicAPIURL     = "https://dabmusic.xyz/api/stream?trackId="
 	qobuzDeebAPIURL         = "https://dab.yeet.su/api/stream?trackId="
 	qobuzAfkarAPIURL        = "https://qbz.afkarxyz.qzz.io/api/track/"
@@ -105,6 +106,10 @@ type QobuzTrack struct {
 		ID   int64  `json:"id"`
 		Name string `json:"name"`
 	} `json:"performer"`
+	Composer struct {
+		ID   int64  `json:"id"`
+		Name string `json:"name"`
+	} `json:"composer"`
 }
 
 type qobuzImageSet struct {
@@ -349,6 +354,7 @@ func qobuzTrackToTrackMetadata(track *QobuzTrack) TrackMetadata {
 		AlbumID:     qobuzPrefixedID(track.Album.ID),
 		ArtistID:    qobuzTrackArtistID(track),
 		AlbumType:   qobuzTrackAlbumType(track),
+		Composer:    strings.TrimSpace(track.Composer.Name),
 	}
 }
 
@@ -373,6 +379,7 @@ func qobuzTrackToAlbumTrackMetadata(track *QobuzTrack) AlbumTrackMetadata {
 		AlbumID:     qobuzPrefixedID(track.Album.ID),
 		AlbumURL:    fmt.Sprintf("https://play.qobuz.com/album/%s", strings.TrimSpace(track.Album.ID)),
 		AlbumType:   qobuzTrackAlbumType(track),
+		Composer:    strings.TrimSpace(track.Composer.Name),
 	}
 }
 
@@ -1030,6 +1037,7 @@ func (q *QobuzDownloader) GetAlbumMetadata(resourceID string) (*AlbumResponsePay
 	}
 
 	tracks := make([]AlbumTrackMetadata, 0, len(album.Tracks.Items))
+	totalDiscs := 0
 	for i := range album.Tracks.Items {
 		track := &album.Tracks.Items[i]
 		track.Album.ID = album.ID
@@ -1041,8 +1049,14 @@ func (q *QobuzDownloader) GetAlbumMetadata(resourceID string) (*AlbumResponsePay
 			Large:     album.Image.Large,
 		}
 		track.Album.TracksCount = album.TracksCount
+		if track.MediaNumber > totalDiscs {
+			totalDiscs = track.MediaNumber
+		}
 		tracks = append(tracks, qobuzTrackToAlbumTrackMetadata(track))
 	}
+	for i := range tracks {
+		tracks[i].TotalDiscs = totalDiscs
+	}
 
 	return &AlbumResponsePayload{
 		AlbumInfo: qobuzAlbumToAlbumInfo(album),
@@ -1126,6 +1140,7 @@ func (q *QobuzDownloader) GetArtistMetadata(resourceID string) (*ArtistResponseP
 func (q *QobuzDownloader) GetAvailableAPIs() []string {
 	return []string{
 		qobuzDownloadAPIURL,
+		qobuzZarzDownloadAPIURL,
 		qobuzDabMusicAPIURL,
 		qobuzDeebAPIURL,
 		qobuzAfkarAPIURL,
@@ -1147,6 +1162,7 @@ const (
 func (q *QobuzDownloader) GetAvailableProviders() []qobuzAPIProvider {
 	return []qobuzAPIProvider{
 		{Name: "musicdl", URL: qobuzDownloadAPIURL, Kind: qobuzAPIKindMusicDL},
+		{Name: "zarz", URL: qobuzZarzDownloadAPIURL, Kind: qobuzAPIKindMusicDL},
 		{Name: "dabmusic", URL: qobuzDabMusicAPIURL, Kind: qobuzAPIKindStandard},
 		{Name: "deeb", URL: qobuzDeebAPIURL, Kind: qobuzAPIKindStandard},
 		{Name: "qbz", URL: qobuzAfkarAPIURL, Kind: qobuzAPIKindStandard},
@@ -2639,17 +2655,8 @@ func resolveQobuzTrackForRequest(req DownloadRequest, downloader *QobuzDownloade
 		}
 	}
 
-	// Strategy 5: Metadata search with strict matching (duration tolerance: 10 seconds)
 	if track == nil {
-		GoLog("[%s] Trying metadata search: '%s' by '%s'\n", logPrefix, req.TrackName, req.ArtistName)
-		track, err = qobuzSearchTrackByMetadataWithDurationFunc(downloader, req.TrackName, req.ArtistName, expectedDurationSec)
-		if track != nil && !qobuzTrackMatchesRequest(req, track, logPrefix, "metadata search", false) {
-			track = nil
-		}
-	}
-
-	if track == nil {
-		errMsg := "could not find matching track on Qobuz (artist/duration mismatch)"
+		errMsg := "could not find matching track on Qobuz without identifier match"
 		if err != nil {
 			errMsg = err.Error()
 		}
@@ -2793,10 +2800,12 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		TrackNumber:   actualTrackNumber,
 		TotalTracks:   req.TotalTracks,
 		DiscNumber:    req.DiscNumber,
+		TotalDiscs:    req.TotalDiscs,
 		ISRC:          track.ISRC,
 		Genre:         req.Genre,
 		Label:         req.Label,
 		Copyright:     req.Copyright,
+		Composer:      req.Composer,
 	}
 
 	var coverData []byte

go_backend/qobuz_test.go

@@ -241,12 +241,13 @@ func TestExtractQobuzAlbumIDsFromArtistHTML(t *testing.T) {
 
 func TestQobuzAvailableProviders(t *testing.T) {
 	providers := NewQobuzDownloader().GetAvailableProviders()
-	if len(providers) != 5 {
-		t.Fatalf("expected 5 Qobuz providers, got %d", len(providers))
+	if len(providers) != 6 {
+		t.Fatalf("expected 6 Qobuz providers, got %d", len(providers))
 	}
 
 	want := map[string]string{
 		"musicdl":  qobuzAPIKindMusicDL,
+		"zarz":     qobuzAPIKindMusicDL,
 		"dabmusic": qobuzAPIKindStandard,
 		"deeb":     qobuzAPIKindStandard,
 		"qbz":      qobuzAPIKindStandard,
@@ -428,11 +429,9 @@ func TestResolveQobuzTrackForRequestRejectsOdesliMismatch(t *testing.T) {
 		t.Fatal("ISRC fallback should not run without an ISRC")
 		return nil, nil
 	}
-	qobuzSearchTrackByMetadataWithDurationFunc = func(_ *QobuzDownloader, trackName, artistName string, expectedDurationSec int) (*QobuzTrack, error) {
-		if trackName != "Taste Back" || artistName != "Harry Styles" || expectedDurationSec != 181 {
-			t.Fatalf("unexpected metadata fallback arguments: %q / %q / %d", trackName, artistName, expectedDurationSec)
-		}
-		return testQobuzTrack(444, "Taste Back", "Harry Styles", 181), nil
+	qobuzSearchTrackByMetadataWithDurationFunc = func(_ *QobuzDownloader, _, _ string, _ int) (*QobuzTrack, error) {
+		t.Fatal("metadata fallback should not run")
+		return nil, nil
 	}
 	songLinkCheckTrackAvailabilityFunc = func(_ *SongLinkClient, _, _ string) (*TrackAvailability, error) {
 		t.Fatal("SongLink should not run when Odesli QobuzID is provided")
@@ -447,11 +446,11 @@ func TestResolveQobuzTrackForRequestRejectsOdesliMismatch(t *testing.T) {
 	}
 
 	track, err := resolveQobuzTrackForRequest(req, &QobuzDownloader{}, "Test")
-	if err != nil {
-		t.Fatalf("expected no error, got %v", err)
+	if err == nil {
+		t.Fatalf("expected error, got track %+v", track)
 	}
-	if track == nil || track.ID != 444 || track.Title != "Taste Back" {
-		t.Fatalf("unexpected resolved track: %+v", track)
+	if track != nil {
+		t.Fatalf("expected nil track, got %+v", track)
 	}
 }
 
@@ -518,3 +517,37 @@ func TestQobuzTrackMatchesRequest_SongLinkBypassesArtistAndTitle(t *testing.T) {
 		t.Fatal("expected SongLink Qobuz source to bypass artist/title verification")
 	}
 }
+
+func TestQobuzTrackMetadataIncludesComposer(t *testing.T) {
+	track := &QobuzTrack{
+		ID:          40681594,
+		Title:       "Sign of the Times",
+		ISRC:        "USSM11703595",
+		Duration:    340,
+		TrackNumber: 1,
+		MediaNumber: 1,
+	}
+	track.Performer.ID = 729886
+	track.Performer.Name = "Harry Styles"
+	track.Composer.ID = 729886
+	track.Composer.Name = "Harry Styles"
+	track.Album.ID = "0886446451985"
+	track.Album.Title = "Harry Styles"
+	track.Album.ReleaseDate = "2017-05-12"
+	track.Album.TracksCount = 10
+	track.Album.ReleaseType = "album"
+	track.Album.ProductType = "album"
+	track.Album.Artist.ID = 729886
+	track.Album.Artist.Name = "Harry Styles"
+	track.Album.Artists = []qobuzArtistRef{{ID: 729886, Name: "Harry Styles"}}
+
+	trackMeta := qobuzTrackToTrackMetadata(track)
+	if trackMeta.Composer != "Harry Styles" {
+		t.Fatalf("track composer = %q", trackMeta.Composer)
+	}
+
+	albumTrackMeta := qobuzTrackToAlbumTrackMetadata(track)
+	if albumTrackMeta.Composer != "Harry Styles" {
+		t.Fatalf("album track composer = %q", albumTrackMeta.Composer)
+	}
+}

go_backend/songlink.go

@@ -147,6 +147,7 @@ func (s *SongLinkClient) doResolveRequest(payload []byte) (map[string]songLinkPl
 		return nil, fmt.Errorf("failed to create resolve request: %w", err)
 	}
 	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("User-Agent", userAgentForURL(req.URL))
 
 	resp, err := s.client.Do(req)
 	if err != nil {
@@ -164,9 +165,9 @@ func (s *SongLinkClient) doResolveRequest(payload []byte) (map[string]songLinkPl
 	}
 
 	var resolveResp struct {
-		Success  bool                           `json:"success"`
-		ISRC     string                         `json:"isrc"`
-		SongUrls map[string]json.RawMessage     `json:"songUrls"`
+		Success  bool                       `json:"success"`
+		ISRC     string                     `json:"isrc"`
+		SongUrls map[string]json.RawMessage `json:"songUrls"`
 	}
 	if err := json.Unmarshal(body, &resolveResp); err != nil {
 		return nil, fmt.Errorf("failed to decode resolve response: %w", err)

go_backend/tidal.go

@@ -51,6 +51,7 @@ type TidalTrack struct {
 	ID           int64  `json:"id"`
 	Title        string `json:"title"`
 	ISRC         string `json:"isrc"`
+	Copyright    string `json:"copyright"`
 	AudioQuality string `json:"audioQuality"`
 	TrackNumber  int    `json:"trackNumber"`
 	VolumeNumber int    `json:"volumeNumber"`
@@ -135,6 +136,7 @@ type tidalPublicAlbum struct {
 	Type           string              `json:"type"`
 	Cover          string              `json:"cover"`
 	ReleaseDate    string              `json:"releaseDate"`
+	Copyright      string              `json:"copyright"`
 	URL            string              `json:"url"`
 	NumberOfTracks int                 `json:"numberOfTracks"`
 	Explicit       bool                `json:"explicit"`
@@ -306,6 +308,29 @@ func tidalTrackArtistsDisplay(track *TidalTrack) string {
 	return strings.TrimSpace(track.Artist.Name)
 }
 
+func tidalTrackAlbumArtistDisplay(track *TidalTrack) string {
+	if track == nil {
+		return ""
+	}
+
+	if len(track.Artists) > 0 {
+		names := make([]string, 0, len(track.Artists))
+		for _, artist := range track.Artists {
+			if strings.ToUpper(strings.TrimSpace(artist.Type)) != "MAIN" {
+				continue
+			}
+			if trimmed := strings.TrimSpace(artist.Name); trimmed != "" {
+				names = append(names, trimmed)
+			}
+		}
+		if len(names) > 0 {
+			return strings.Join(names, ", ")
+		}
+	}
+
+	return strings.TrimSpace(track.Artist.Name)
+}
+
 func tidalAlbumArtistsDisplay(album *tidalPublicAlbum) string {
 	if album == nil {
 		return ""
@@ -354,7 +379,7 @@ func tidalTrackToTrackMetadata(track *TidalTrack) TrackMetadata {
 		Artists:     tidalTrackArtistsDisplay(track),
 		Name:        strings.TrimSpace(track.Title),
 		AlbumName:   strings.TrimSpace(track.Album.Title),
-		AlbumArtist: strings.TrimSpace(track.Artist.Name),
+		AlbumArtist: tidalTrackAlbumArtistDisplay(track),
 		DurationMS:  track.Duration * 1000,
 		Images:      tidalImageURL(track.Album.Cover, "1280x1280"),
 		ReleaseDate: strings.TrimSpace(track.Album.ReleaseDate),
@@ -377,7 +402,7 @@ func tidalTrackToAlbumTrackMetadata(track *TidalTrack) AlbumTrackMetadata {
 		Artists:     tidalTrackArtistsDisplay(track),
 		Name:        strings.TrimSpace(track.Title),
 		AlbumName:   strings.TrimSpace(track.Album.Title),
-		AlbumArtist: strings.TrimSpace(track.Artist.Name),
+		AlbumArtist: tidalTrackAlbumArtistDisplay(track),
 		DurationMS:  track.Duration * 1000,
 		Images:      tidalImageURL(track.Album.Cover, "1280x1280"),
 		ReleaseDate: strings.TrimSpace(track.Album.ReleaseDate),
@@ -407,6 +432,7 @@ func tidalAlbumToAlbumInfo(album *tidalPublicAlbum) AlbumInfoMetadata {
 		Artists:     tidalAlbumArtistsDisplay(album),
 		ArtistId:    artistID,
 		Images:      tidalImageURL(album.Cover, "1280x1280"),
+		Copyright:   strings.TrimSpace(album.Copyright),
 	}
 }
 
@@ -688,6 +714,10 @@ func findTidalArtistPageModule(page *tidalPublicArtistPage, moduleType string) *
 
 func (t *TidalDownloader) GetAvailableAPIs() []string {
 	return []string{
+		"https://eu-central.monochrome.tf",
+		"https://us-west.monochrome.tf",
+		"https://api.monochrome.tf",
+		"https://monochrome-api.samidy.com",
 		"https://tidal-api.binimum.org",
 		"https://tidal.kinoplus.online",
 		"https://triton.squid.wtf",
@@ -1012,6 +1042,7 @@ func (t *TidalDownloader) GetAlbumMetadata(resourceID string) (*AlbumResponsePay
 	}
 
 	tracks := make([]AlbumTrackMetadata, 0, len(itemsModule.PagedList.Items))
+	totalDiscs := 0
 	for _, item := range itemsModule.PagedList.Items {
 		track := item.Item
 		track.Album.ID = headerModule.Album.ID
@@ -1019,8 +1050,14 @@ func (t *TidalDownloader) GetAlbumMetadata(resourceID string) (*AlbumResponsePay
 		track.Album.Cover = headerModule.Album.Cover
 		track.Album.ReleaseDate = headerModule.Album.ReleaseDate
 		track.Album.URL = headerModule.Album.URL
+		if track.VolumeNumber > totalDiscs {
+			totalDiscs = track.VolumeNumber
+		}
 		tracks = append(tracks, tidalTrackToAlbumTrackMetadata(&track))
 	}
+	for i := range tracks {
+		tracks[i].TotalDiscs = totalDiscs
+	}
 
 	return &AlbumResponsePayload{
 		AlbumInfo: tidalAlbumToAlbumInfo(&headerModule.Album),
@@ -1729,6 +1766,7 @@ type TidalDownloadResult struct {
 	TrackNumber int
 	DiscNumber  int
 	ISRC        string
+	Copyright   string
 	LyricsLRC   string // LRC content for embedding in converted files
 }
 
@@ -2042,18 +2080,6 @@ func resolveTidalTrackForRequest(req DownloadRequest, downloader *TidalDownloade
 		}
 	}
 
-	if !gotTidalID && req.ISRC != "" {
-		GoLog("[%s] Trying direct Tidal ISRC search: %s\n", logPrefix, req.ISRC)
-		directTrack, directErr := downloader.SearchTrackByISRC(req.ISRC)
-		if directErr == nil && directTrack != nil && directTrack.ID > 0 {
-			trackID = directTrack.ID
-			gotTidalID = true
-			GoLog("[%s] Got Tidal ID %d from direct ISRC search\n", logPrefix, trackID)
-		} else if directErr != nil {
-			GoLog("[%s] Direct Tidal ISRC search failed: %v\n", logPrefix, directErr)
-		}
-	}
-
 	if !gotTidalID && req.ISRC != "" && req.TrackName != "" && req.ArtistName != "" {
 		GoLog("[%s] Trying Tidal public metadata search with ISRC\n", logPrefix)
 		searchTrack, searchErr := downloader.SearchTrackByMetadataWithISRC(
@@ -2349,6 +2375,10 @@ func downloadFromTidal(req DownloadRequest) (TidalDownloadResult, error) {
 	if actualDiscNumber == 0 {
 		actualDiscNumber = track.VolumeNumber
 	}
+	copyright := strings.TrimSpace(req.Copyright)
+	if copyright == "" {
+		copyright = strings.TrimSpace(track.Copyright)
+	}
 
 	metadata := Metadata{
 		Title:         req.TrackName,
@@ -2360,10 +2390,12 @@ func downloadFromTidal(req DownloadRequest) (TidalDownloadResult, error) {
 		TrackNumber:   actualTrackNumber,
 		TotalTracks:   req.TotalTracks,
 		DiscNumber:    actualDiscNumber,
+		TotalDiscs:    req.TotalDiscs,
 		ISRC:          track.ISRC,
 		Genre:         req.Genre,
 		Label:         req.Label,
-		Copyright:     req.Copyright,
+		Copyright:     copyright,
+		Composer:      req.Composer,
 	}
 
 	var coverData []byte
@@ -2473,6 +2505,7 @@ func downloadFromTidal(req DownloadRequest) (TidalDownloadResult, error) {
 		TrackNumber: resultTrackNumber,
 		DiscNumber:  resultDiscNumber,
 		ISRC:        track.ISRC,
+		Copyright:   copyright,
 		LyricsLRC:   lyricsLRC,
 	}, nil
 }

ios/Runner/AppDelegate.swift

@@ -22,6 +22,9 @@ import Gobackend  // Import Go framework
         _ application: UIApplication,
         didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
     ) -> Bool {
+        if let version = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String {
+            GobackendSetAppVersion(version)
+        }
         
         let controller = window?.rootViewController as! FlutterViewController
         let channel = FlutterMethodChannel(
@@ -66,9 +69,59 @@ import Gobackend  // Import Go framework
         )
         
         GeneratedPluginRegistrant.register(with: self)
+        if let url = launchOptions?[.url] as? URL {
+            _ = handleExtensionOAuthRedirect(url: url)
+        }
         return super.application(application, didFinishLaunchingWithOptions: launchOptions)
     }
 
+    /// PKCE OAuth return URL: spotiflac://callback?code=...&state=<extension_id>
+    @discardableResult
+    private func handleExtensionOAuthRedirect(url: URL) -> Bool {
+        guard let scheme = url.scheme?.lowercased(), scheme == "spotiflac" else { return false }
+        let host = (url.host ?? "").lowercased()
+        let path = url.path.lowercased()
+        let ok =
+            host == "callback" || host == "spotify-callback" || path.contains("callback")
+        guard ok else { return false }
+        guard let components = URLComponents(url: url, resolvingAgainstBaseURL: false) else {
+            return false
+        }
+        let q = components.queryItems ?? []
+        let code =
+            q.first { $0.name == "code" }?.value?.trimmingCharacters(
+                in: .whitespacesAndNewlines) ?? ""
+        let state =
+            q.first { $0.name == "state" }?.value?.trimmingCharacters(
+                in: .whitespacesAndNewlines) ?? ""
+        if code.isEmpty { return false }
+        if state.isEmpty {
+            NSLog("SpotiFLAC: Extension OAuth redirect missing state (extension id)")
+            return false
+        }
+        streamQueue.async {
+            var err: NSError?
+            GobackendSetExtensionAuthCodeByID(state, code)
+            _ = GobackendInvokeExtensionActionJSON(state, "completeSpotifyLogin", &err)
+            if let err = err {
+                NSLog(
+                    "SpotiFLAC: Extension OAuth complete failed: \(err.localizedDescription)")
+            }
+        }
+        return true
+    }
+
+    override func application(
+        _ app: UIApplication,
+        open url: URL,
+        options: [UIApplication.OpenURLOptionsKey: Any] = [:]
+    ) -> Bool {
+        if handleExtensionOAuthRedirect(url: url) {
+            return true
+        }
+        return super.application(app, open: url, options: options)
+    }
+
     deinit {
         stopDownloadProgressStream()
         stopLibraryScanProgressStream()
@@ -371,16 +424,6 @@ import Gobackend  // Import Go framework
             if let error = error { throw error }
             return response
             
-        case "searchDeezerAll":
-            let args = call.arguments as! [String: Any]
-            let query = args["query"] as! String
-            let trackLimit = args["track_limit"] as? Int ?? 15
-            let artistLimit = args["artist_limit"] as? Int ?? 3
-            let filter = args["filter"] as? String ?? ""
-            let response = GobackendSearchDeezerAll(query, Int(trackLimit), Int(artistLimit), filter, &error)
-            if let error = error { throw error }
-            return response
-
         case "searchTidalAll":
             let args = call.arguments as! [String: Any]
             let query = args["query"] as! String
@@ -607,6 +650,13 @@ import Gobackend  // Import Go framework
             let response = GobackendGetProviderPriorityJSON(&error)
             if let error = error { throw error }
             return response
+
+        case "setDownloadFallbackExtensionIds":
+            let args = call.arguments as! [String: Any]
+            let extensionIdsJson = args["extension_ids"] as? String ?? ""
+            GobackendSetExtensionFallbackProviderIDsJSON(extensionIdsJson, &error)
+            if let error = error { throw error }
+            return nil
             
         case "setMetadataProviderPriority":
             let args = call.arguments as! [String: Any]

lib/constants/app_info.dart

@@ -3,8 +3,8 @@ import 'package:flutter/foundation.dart';
 /// App version and info constants
 /// Update version here only - all other files will reference this
 class AppInfo {
-  static const String version = '4.2.0';
-  static const String buildNumber = '121';
+  static const String version = '4.3.1';
+  static const String buildNumber = '126';
   static const String fullVersion = '$version+$buildNumber';
 
   /// Shows "Internal" in debug builds, actual version in release.

lib/l10n/app_localizations.dart

@@ -17,6 +17,7 @@ import 'app_localizations_nl.dart';
 import 'app_localizations_pt.dart';
 import 'app_localizations_ru.dart';
 import 'app_localizations_tr.dart';
+import 'app_localizations_uk.dart';
 import 'app_localizations_zh.dart';
 
 // ignore_for_file: type=lint
@@ -119,6 +120,7 @@ abstract class AppLocalizations {
     Locale('pt', 'PT'),
     Locale('ru'),
     Locale('tr'),
+    Locale('uk'),
     Locale('zh'),
     Locale('zh', 'CN'),
     Locale('zh', 'TW'),
@@ -352,6 +354,18 @@ abstract class AppLocalizations {
   /// **'Using extension: {extensionName}'**
   String optionsUsingExtension(String extensionName);
 
+  /// Title for the preferred default search tab setting
+  ///
+  /// In en, this message translates to:
+  /// **'Default Search Tab'**
+  String get optionsDefaultSearchTab;
+
+  /// Subtitle for the preferred default search tab setting
+  ///
+  /// In en, this message translates to:
+  /// **'Choose which tab opens first for new search results.'**
+  String get optionsDefaultSearchTabSubtitle;
+
   /// Hint to switch back to built-in providers
   ///
   /// In en, this message translates to:
@@ -718,6 +732,12 @@ abstract class AppLocalizations {
   /// **'PC source code'**
   String get aboutPCSource;
 
+  /// Link to Keep Android Open campaign website
+  ///
+  /// In en, this message translates to:
+  /// **'Keep Android Open'**
+  String get aboutKeepAndroidOpen;
+
   /// Link to report bugs
   ///
   /// In en, this message translates to:
@@ -1738,6 +1758,24 @@ abstract class AppLocalizations {
   /// **'If a track is not available on the first provider, the app will automatically try the next one.'**
   String get providerPriorityInfo;
 
+  /// Section title for choosing which download extensions can be used as fallback providers
+  ///
+  /// In en, this message translates to:
+  /// **'Extension Fallback'**
+  String get providerPriorityFallbackExtensionsTitle;
+
+  /// Section description for extension fallback selection
+  ///
+  /// In en, this message translates to:
+  /// **'Choose which installed download extensions can be used during automatic fallback. Built-in providers still follow the priority order above.'**
+  String get providerPriorityFallbackExtensionsDescription;
+
+  /// Hint below the extension fallback selection list
+  ///
+  /// In en, this message translates to:
+  /// **'Only enabled extensions with download-provider capability are listed here.'**
+  String get providerPriorityFallbackExtensionsHint;
+
   /// Label for built-in providers (Tidal/Qobuz)
   ///
   /// In en, this message translates to:
@@ -2644,6 +2682,18 @@ abstract class AppLocalizations {
   /// **'Set download service order'**
   String get extensionsDownloadPrioritySubtitle;
 
+  /// Setting and page title for choosing which download extensions can be used during fallback
+  ///
+  /// In en, this message translates to:
+  /// **'Fallback Extensions'**
+  String get extensionsFallbackTitle;
+
+  /// Subtitle for download fallback extensions menu
+  ///
+  /// In en, this message translates to:
+  /// **'Choose which installed download extensions can be used as fallback'**
+  String get extensionsFallbackSubtitle;
+
   /// Empty state - no download providers
   ///
   /// In en, this message translates to:
@@ -5809,6 +5859,7 @@ class _AppLocalizationsDelegate
     'pt',
     'ru',
     'tr',
+    'uk',
     'zh',
   ].contains(locale.languageCode);
 
@@ -5873,6 +5924,8 @@ AppLocalizations lookupAppLocalizations(Locale locale) {
       return AppLocalizationsRu();
     case 'tr':
       return AppLocalizationsTr();
+    case 'uk':
+      return AppLocalizationsUk();
     case 'zh':
       return AppLocalizationsZh();
   }

lib/l10n/app_localizations_de.dart

@@ -21,13 +21,13 @@ class AppLocalizationsDe extends AppLocalizations {
   String get navSettings => 'Einstellungen';
 
   @override
-  String get navStore => 'Store';
+  String get navStore => 'Repo';
 
   @override
   String get homeTitle => 'Startseite';
 
   @override
-  String get homeSubtitle => 'Spotify-Link einfügen oder nach Namen suchen';
+  String get homeSubtitle => 'Unterstützte URL einfügen oder nach Namen suchen';
 
   @override
   String get homeSupports =>
@@ -129,6 +129,13 @@ class AppLocalizationsDe extends AppLocalizations {
     return 'Erweiterung verwenden: $extensionName';
   }
 
+  @override
+  String get optionsDefaultSearchTab => 'Default Search Tab';
+
+  @override
+  String get optionsDefaultSearchTabSubtitle =>
+      'Choose which tab opens first for new search results.';
+
   @override
   String get optionsSwitchBack =>
       'Tippe auf Deezer oder Spotify, um von der Erweiterung zurückzuwechseln';
@@ -177,21 +184,21 @@ class AppLocalizationsDe extends AppLocalizations {
       'Disabled: no loudness normalization tags';
 
   @override
-  String get optionsArtistTagMode => 'Artist Tag Mode';
+  String get optionsArtistTagMode => 'Künstler Tag-Modus';
 
   @override
   String get optionsArtistTagModeDescription =>
-      'Choose how multiple artists are written into embedded tags.';
+      'Wähle aus, wie mehrere Künstler in eingebetteten Tags geschrieben sind.';
 
   @override
-  String get optionsArtistTagModeJoined => 'Single joined value';
+  String get optionsArtistTagModeJoined => 'Einzelne beigefügte Werte';
 
   @override
   String get optionsArtistTagModeJoinedSubtitle =>
-      'Write one ARTIST value like \"Artist A, Artist B\" for maximum player compatibility.';
+      'Einen Künstler wert wie \"Artist A, Artist B\" für maximale Spieler-Kompatibilität schreiben.';
 
   @override
-  String get optionsArtistTagModeSplitVorbis => 'Split tags for FLAC/Opus';
+  String get optionsArtistTagModeSplitVorbis => 'Tags für FLAC/Opus aufteilen';
 
   @override
   String get optionsArtistTagModeSplitVorbisSubtitle =>
@@ -213,11 +220,11 @@ class AppLocalizationsDe extends AppLocalizations {
       'Parallele Downloads können Ratenlimitierung auslösen';
 
   @override
-  String get optionsExtensionStore => 'Erweiterungs-Store';
+  String get optionsExtensionStore => 'Erweiterungs-Repo';
 
   @override
   String get optionsExtensionStoreSubtitle =>
-      'Store-Tab in Navigation anzeigen';
+      'Repo-Tab in der Navigation anzeigen';
 
   @override
   String get optionsCheckUpdates => 'Nach Updates suchen';
@@ -296,7 +303,7 @@ class AppLocalizationsDe extends AppLocalizations {
   String get extensionsUninstall => 'Deinstallieren';
 
   @override
-  String get storeTitle => 'Erweiterungs-Store';
+  String get storeTitle => 'Erweiterungs-Repo';
 
   @override
   String get storeSearch => 'Erweiterungen suchen...';
@@ -341,6 +348,9 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get aboutPCSource => 'PC Quellcode';
 
+  @override
+  String get aboutKeepAndroidOpen => 'Keep Android Open';
+
   @override
   String get aboutReportIssue => 'Problem melden';
 
@@ -576,7 +586,7 @@ class AppLocalizationsDe extends AppLocalizations {
   String get dialogImport => 'Importieren';
 
   @override
-  String get dialogDownload => 'Download';
+  String get dialogDownload => 'Herunterladen';
 
   @override
   String get dialogDiscard => 'Verwerfen';
@@ -809,37 +819,37 @@ class AppLocalizationsDe extends AppLocalizations {
   String get searchAlbums => 'Alben';
 
   @override
-  String get searchPlaylists => 'Playlisten';
+  String get searchPlaylists => 'Playlists';
 
   @override
-  String get searchSortTitle => 'Sort Results';
+  String get searchSortTitle => 'Ergebnisse sortieren';
 
   @override
-  String get searchSortDefault => 'Default';
+  String get searchSortDefault => 'Standard';
 
   @override
-  String get searchSortTitleAZ => 'Title (A-Z)';
+  String get searchSortTitleAZ => 'Titel (A-Z)';
 
   @override
-  String get searchSortTitleZA => 'Title (Z-A)';
+  String get searchSortTitleZA => 'Titel (Z-A)';
 
   @override
-  String get searchSortArtistAZ => 'Artist (A-Z)';
+  String get searchSortArtistAZ => 'Künstler (A-Z)';
 
   @override
-  String get searchSortArtistZA => 'Artist (Z-A)';
+  String get searchSortArtistZA => 'Künstler (Z-A)';
 
   @override
-  String get searchSortDurationShort => 'Duration (Shortest)';
+  String get searchSortDurationShort => 'Dauer (kürzeste)';
 
   @override
-  String get searchSortDurationLong => 'Duration (Longest)';
+  String get searchSortDurationLong => 'Dauer (längste)';
 
   @override
-  String get searchSortDateOldest => 'Release Date (Oldest)';
+  String get searchSortDateOldest => 'Veröffentlichungsdatum (älteste)';
 
   @override
-  String get searchSortDateNewest => 'Release Date (Newest)';
+  String get searchSortDateNewest => 'Veröffentlichungsdatum (Neueste)';
 
   @override
   String get tooltipPlay => 'Abspielen';
@@ -940,6 +950,17 @@ class AppLocalizationsDe extends AppLocalizations {
   String get providerPriorityInfo =>
       'Wenn kein Titel bei dem ersten Anbieter nicht verfügbar ist, wird die App automatisch den nächsten versuchen.';
 
+  @override
+  String get providerPriorityFallbackExtensionsTitle => 'Extension Fallback';
+
+  @override
+  String get providerPriorityFallbackExtensionsDescription =>
+      'Choose which installed download extensions can be used during automatic fallback. Built-in providers still follow the priority order above.';
+
+  @override
+  String get providerPriorityFallbackExtensionsHint =>
+      'Only enabled extensions with download-provider capability are listed here.';
+
   @override
   String get providerBuiltIn => 'Integriert';
 
@@ -1294,36 +1315,36 @@ class AppLocalizationsDe extends AppLocalizations {
   String get storeClearFilters => 'Filter entfernen';
 
   @override
-  String get storeAddRepoTitle => 'Add Extension Repository';
+  String get storeAddRepoTitle => 'Erweiterungs-Repository hinzufügen';
 
   @override
   String get storeAddRepoDescription =>
-      'Enter a GitHub repository URL that contains a registry.json file to browse and install extensions.';
+      'Gib eine GitHub Repository-URL ein, die eine Registry.json Datei enthält, um Erweiterungen zu durchsuchen und zu installieren.';
 
   @override
-  String get storeRepoUrlLabel => 'Repository URL';
+  String get storeRepoUrlLabel => 'Repository-URL';
 
   @override
   String get storeRepoUrlHint => 'https://github.com/user/repo';
 
   @override
   String get storeRepoUrlHelper =>
-      'e.g. https://github.com/user/extensions-repo';
+      'z.B. https://github.com/user/extensions-repo';
 
   @override
-  String get storeAddRepoButton => 'Add Repository';
+  String get storeAddRepoButton => 'Repository hinzufügen';
 
   @override
-  String get storeChangeRepoTooltip => 'Change repository';
+  String get storeChangeRepoTooltip => 'Repository ändern';
 
   @override
-  String get storeRepoDialogTitle => 'Extension Repository';
+  String get storeRepoDialogTitle => 'Erweiterungs-Repository';
 
   @override
-  String get storeRepoDialogCurrent => 'Current repository:';
+  String get storeRepoDialogCurrent => 'Aktuelles Repository:';
 
   @override
-  String get storeNewRepoUrlLabel => 'New Repository URL';
+  String get storeNewRepoUrlLabel => 'Neue Repository-URL';
 
   @override
   String get storeLoadError => 'Failed to load repository';
@@ -1335,7 +1356,7 @@ class AppLocalizationsDe extends AppLocalizations {
   String get storeEmptyNoResults => 'No extensions found';
 
   @override
-  String get extensionDefaultProvider => 'Standard (Deezer/Spotify)';
+  String get extensionDefaultProvider => 'Standard (Deezer)';
 
   @override
   String get extensionDefaultProviderSubtitle => 'Eingebaute Suche verwenden';
@@ -1438,6 +1459,13 @@ class AppLocalizationsDe extends AppLocalizations {
   String get extensionsDownloadPrioritySubtitle =>
       'Download-Service-Reihenfolge festlegen';
 
+  @override
+  String get extensionsFallbackTitle => 'Fallback Extensions';
+
+  @override
+  String get extensionsFallbackSubtitle =>
+      'Choose which installed download extensions can be used as fallback';
+
   @override
   String get extensionsNoDownloadProvider =>
       'Keine Erweiterungen mit Download-Provider';
@@ -1489,36 +1517,36 @@ class AppLocalizationsDe extends AppLocalizations {
   String get qualityHiResFlacMaxSubtitle => '24-Bit / bis 192kHz';
 
   @override
-  String get downloadLossy320 => 'Lossy 320kbps';
+  String get downloadLossy320 => 'Verlustbehaftet 320kbps';
 
   @override
-  String get downloadLossyFormat => 'Lossy Format';
+  String get downloadLossyFormat => 'Verlustbehaftetes Format';
 
   @override
   String get downloadLossy320Format => 'Lossy 320kbps Format';
 
   @override
   String get downloadLossy320FormatDesc =>
-      'Choose the output format for Tidal 320kbps lossy downloads. The original AAC stream will be converted to your selected format.';
+      'Wähle das Ausgabeformat für Tidal 320kbps verlustbehaftete Downloads. Der ursprüngliche AAC Stream wird in das ausgewählte Format konvertiert.';
 
   @override
   String get downloadLossyMp3 => 'MP3 320kbps';
 
   @override
-  String get downloadLossyMp3Subtitle => 'Best compatibility, ~10MB per track';
+  String get downloadLossyMp3Subtitle =>
+      'Beste Kompatibilität, ~10MB pro Titel';
 
   @override
   String get downloadLossyOpus256 => 'Opus 256kbps';
 
   @override
-  String get downloadLossyOpus256Subtitle =>
-      'Best quality Opus, ~8MB per track';
+  String get downloadLossyOpus256Subtitle => 'Beste Qualität, ~8MB pro Titel';
 
   @override
   String get downloadLossyOpus128 => 'Opus 128kbps';
 
   @override
-  String get downloadLossyOpus128Subtitle => 'Smallest size, ~4MB per track';
+  String get downloadLossyOpus128Subtitle => 'Kleinste Größe, ~4MB pro Track';
 
   @override
   String get qualityNote =>
@@ -1828,23 +1856,23 @@ class AppLocalizationsDe extends AppLocalizations {
       'Bei der Suche nach vorhandenen Titeln anzeigen';
 
   @override
-  String get libraryAutoScan => 'Auto Scan';
+  String get libraryAutoScan => 'Auto-Scan';
 
   @override
   String get libraryAutoScanSubtitle =>
       'Automatically scan your library for new files';
 
   @override
-  String get libraryAutoScanOff => 'Off';
+  String get libraryAutoScanOff => 'Aus';
 
   @override
-  String get libraryAutoScanOnOpen => 'Every app open';
+  String get libraryAutoScanOnOpen => 'Bei jeder App Öffnung';
 
   @override
-  String get libraryAutoScanDaily => 'Daily';
+  String get libraryAutoScanDaily => 'Täglich';
 
   @override
-  String get libraryAutoScanWeekly => 'Weekly';
+  String get libraryAutoScanWeekly => 'Wöchentlich';
 
   @override
   String get libraryActions => 'Aktionen';
@@ -1901,8 +1929,8 @@ class AppLocalizationsDe extends AppLocalizations {
     String _temp0 = intl.Intl.pluralLogic(
       count,
       locale: localeName,
-      other: 'files',
-      one: 'file',
+      other: '$count Datein',
+      one: '1 Datei',
     );
     return '$_temp0';
   }
@@ -1919,7 +1947,7 @@ class AppLocalizationsDe extends AppLocalizations {
   String get libraryScanning => 'Scannen...';
 
   @override
-  String get libraryScanFinalizing => 'Finalizing library...';
+  String get libraryScanFinalizing => 'Bibliothek wird aktualisiert...';
 
   @override
   String libraryScanProgress(String progress, int total) {
@@ -1990,22 +2018,23 @@ class AppLocalizationsDe extends AppLocalizations {
   String get libraryFilterFormat => 'Format';
 
   @override
-  String get libraryFilterMetadata => 'Metadata';
+  String get libraryFilterMetadata => 'Metadaten';
 
   @override
-  String get libraryFilterMetadataComplete => 'Complete metadata';
+  String get libraryFilterMetadataComplete => 'Komplette Metadaten';
 
   @override
-  String get libraryFilterMetadataMissingAny => 'Missing any metadata';
+  String get libraryFilterMetadataMissingAny => 'Metadaten fehlen';
 
   @override
-  String get libraryFilterMetadataMissingYear => 'Missing year';
+  String get libraryFilterMetadataMissingYear => 'Jahr fehlt';
 
   @override
-  String get libraryFilterMetadataMissingGenre => 'Missing genre';
+  String get libraryFilterMetadataMissingGenre => 'Genre fehlt';
 
   @override
-  String get libraryFilterMetadataMissingAlbumArtist => 'Missing album artist';
+  String get libraryFilterMetadataMissingAlbumArtist =>
+      'Fehlender Album-Künstler';
 
   @override
   String get libraryFilterSort => 'Sortieren';
@@ -2037,7 +2066,7 @@ class AppLocalizationsDe extends AppLocalizations {
       count,
       locale: localeName,
       other: 'vor $count Minuten',
-      one: 'vor $count Minute',
+      one: 'vor 1 Minute',
     );
     return '$_temp0';
   }
@@ -2048,7 +2077,7 @@ class AppLocalizationsDe extends AppLocalizations {
       count,
       locale: localeName,
       other: 'vor $count Stunden',
-      one: 'vor $count Stunde',
+      one: 'vor 1 Stunde',
     );
     return '$_temp0';
   }
@@ -2114,7 +2143,7 @@ class AppLocalizationsDe extends AppLocalizations {
 
   @override
   String get tutorialExtensionsTip1 =>
-      'Im Store Tab findest du nützliche Erweiterungen';
+      'Browse the Repo tab to discover useful extensions';
 
   @override
   String get tutorialExtensionsTip2 =>
@@ -2368,11 +2397,11 @@ class AppLocalizationsDe extends AppLocalizations {
       'FFmpeg Metadaten-Einbettung fehlgeschlagen';
 
   @override
-  String get queueFlacAction => 'Queue FLAC';
+  String get queueFlacAction => 'Warteschlange FLAC';
 
   @override
   String queueFlacConfirmMessage(int count) {
-    return 'Search online matches for the selected tracks and queue FLAC downloads.\n\nExisting files will not be modified or deleted.\n\nOnly high-confidence matches are queued automatically.\n\n$count selected';
+    return 'Suche Online-Matches für ausgewählte Titel und Playlists für FLAC-Downloads.\n\nVorhandene Dateien werden weder geändert noch gelöscht.\n\nNur eindeutige Treffer werden automatisch zur Warteschlange hinzugefügt.\n\n$count ausgewählt';
   }
 
   @override
@@ -2398,7 +2427,8 @@ class AppLocalizationsDe extends AppLocalizations {
   String get trackConvertFormat => 'Format konvertieren';
 
   @override
-  String get trackConvertFormatSubtitle => 'In MP3 oder Opus konvertieren';
+  String get trackConvertFormatSubtitle =>
+      'Convert to MP3, Opus, ALAC, or FLAC';
 
   @override
   String get trackConvertTitle => 'Audio konvertieren';
@@ -2426,7 +2456,7 @@ class AppLocalizationsDe extends AppLocalizations {
     String sourceFormat,
     String targetFormat,
   ) {
-    return 'Convert from $sourceFormat to $targetFormat? (Lossless — no quality loss)\n\nThe original file will be deleted after conversion.';
+    return 'Konvertieren von $sourceFormat in $targetFormat? (kein Qualitätsverlust)\n\nDie Originaldatei wird nach der Konvertierung gelöscht.';
   }
 
   @override
@@ -2506,7 +2536,7 @@ class AppLocalizationsDe extends AppLocalizations {
   String get collectionLoved => 'Lieblingssongs';
 
   @override
-  String get collectionPlaylists => 'Playlisten';
+  String get collectionPlaylists => 'Playlists';
 
   @override
   String get collectionPlaylist => 'Playlist';
@@ -2693,10 +2723,10 @@ class AppLocalizationsDe extends AppLocalizations {
     String _temp0 = intl.Intl.pluralLogic(
       count,
       locale: localeName,
-      other: 'tracks',
-      one: 'track',
+      other: 'Titel',
+      one: 'Titel',
     );
-    return 'Convert $count $_temp0 to $format? (Lossless — no quality loss)\n\nOriginal files will be deleted after conversion.';
+    return 'Konvertiere $count $_temp0 in $format? (kein Qualitätsverlust)\n\nOriginaldateien werden nach der Konvertierung gelöscht.';
   }
 
   @override
@@ -2723,24 +2753,24 @@ class AppLocalizationsDe extends AppLocalizations {
       'Künstler-Ordner nur für Titel-Künstler';
 
   @override
-  String get lyricsProvidersTitle => 'Lyrics Providers';
+  String get lyricsProvidersTitle => 'Lyrics-Anbieter';
 
   @override
   String get lyricsProvidersDescription =>
-      'Enable, disable and reorder lyrics sources. Providers are tried top-to-bottom until lyrics are found.';
+      'Lyrics aktivieren, deaktivieren und neu ordnen. Anbieter werden von oben nach unten ausprobiert, bis Lyrics gefunden werden.';
 
   @override
   String get lyricsProvidersInfoText =>
-      'Extension lyrics providers always run before built-in providers. At least one provider must remain enabled.';
+      'Erweiterungsanbieter werden immer vor eingebauten ausgeführt. Mindestens ein Anbieter muss aktiviert bleiben.';
 
   @override
   String lyricsProvidersEnabledSection(int count) {
-    return 'Enabled ($count)';
+    return '($count) aktiviert';
   }
 
   @override
   String lyricsProvidersDisabledSection(int count) {
-    return 'Disabled ($count)';
+    return '($count) deaktiviert';
   }
 
   @override
@@ -2759,52 +2789,53 @@ class AppLocalizationsDe extends AppLocalizations {
 
   @override
   String get lyricsProviderNeteaseDesc =>
-      'NetEase Cloud Music (good for Asian songs)';
+      'NetEase Cloud Music (gut für asiatische Lieder)';
 
   @override
   String get lyricsProviderMusixmatchDesc =>
-      'Largest lyrics database (multi-language)';
+      'Größte Lyrics-Datenbank (mehrsprachig)';
 
   @override
   String get lyricsProviderAppleMusicDesc =>
-      'Word-by-word synced lyrics (via proxy)';
+      'Wort-für-Wort-synchronisierte Lyrics (via Proxy)';
 
   @override
   String get lyricsProviderQqMusicDesc =>
-      'QQ Music (good for Chinese songs, via proxy)';
+      'QQ Music (gut für chinesische Lieder, via Proxy)';
 
   @override
-  String get lyricsProviderExtensionDesc => 'Extension provider';
+  String get lyricsProviderExtensionDesc => 'Erweiterungsanbieter';
 
   @override
-  String get safMigrationTitle => 'Storage Update Required';
+  String get safMigrationTitle => 'Speicheraktualisierung erforderlich';
 
   @override
   String get safMigrationMessage1 =>
-      'SpotiFLAC now uses Android Storage Access Framework (SAF) for downloads. This fixes \"permission denied\" errors on Android 10+.';
+      'SpotiFLAC verwendet jetzt Android Storage Access Framework (SAF) beim Herunterladen. Dies behebt Fehler bei Android 10+.';
 
   @override
   String get safMigrationMessage2 =>
-      'Please select your download folder again to switch to the new storage system.';
+      'Bitte wähle dein Download-Ordner erneut aus, um zum neuen System zu wechseln.';
 
   @override
   String get safMigrationSuccess => 'Download folder updated to SAF mode';
 
   @override
-  String get settingsDonate => 'Donate';
+  String get settingsDonate => 'Unterstützen';
 
   @override
-  String get settingsDonateSubtitle => 'Support SpotiFLAC-Mobile development';
+  String get settingsDonateSubtitle =>
+      'Unterstütze die SpotiFLAC-Mobile Entwickler';
 
   @override
-  String get tooltipLoveAll => 'Love All';
+  String get tooltipLoveAll => 'Alle lieben';
 
   @override
-  String get tooltipAddToPlaylist => 'Add to Playlist';
+  String get tooltipAddToPlaylist => 'Zur Wiedergabeliste hinzufügen';
 
   @override
   String snackbarRemovedTracksFromLoved(int count) {
-    return 'Removed $count tracks from Loved';
+    return '$count Titel von geliebt entfernt';
   }
 
   @override
@@ -2813,7 +2844,7 @@ class AppLocalizationsDe extends AppLocalizations {
   }
 
   @override
-  String get dialogDownloadAllTitle => 'Download All';
+  String get dialogDownloadAllTitle => 'Alle Herunterladen';
 
   @override
   String dialogDownloadAllMessage(int count) {
@@ -2824,7 +2855,7 @@ class AppLocalizationsDe extends AppLocalizations {
   String get homeSkipAlreadyDownloaded => 'Skip already downloaded songs';
 
   @override
-  String get homeGoToAlbum => 'Go to Album';
+  String get homeGoToAlbum => 'Zum Album gehen';
 
   @override
   String get homeAlbumInfoUnavailable => 'Album info not available';
@@ -2843,7 +2874,7 @@ class AppLocalizationsDe extends AppLocalizations {
 
   @override
   String snackbarError(String error) {
-    return 'Error: $error';
+    return 'Fehler: $error';
   }
 
   @override
@@ -2863,7 +2894,7 @@ class AppLocalizationsDe extends AppLocalizations {
   String get storageModeAppFolderSubtitle => 'Use default Music/SpotiFLAC path';
 
   @override
-  String get storageModeSaf => 'SAF folder';
+  String get storageModeSaf => 'SAF-Ordner';
 
   @override
   String get storageModeSafSubtitle =>
@@ -2874,7 +2905,7 @@ class AppLocalizationsDe extends AppLocalizations {
       'Customize how your files are named.';
 
   @override
-  String get downloadFilenameInsertTag => 'Tap to insert tag:';
+  String get downloadFilenameInsertTag => 'Tippe, um Tag einzufügen:';
 
   @override
   String get downloadSeparateSinglesEnabled => 'Albums/ and Singles/ folders';
@@ -2902,10 +2933,10 @@ class AppLocalizationsDe extends AppLocalizations {
       'By Playlist already places downloads inside a playlist folder.';
 
   @override
-  String get downloadSongLinkRegion => 'SongLink Region';
+  String get downloadSongLinkRegion => 'SongLink-Region';
 
   @override
-  String get downloadNetworkCompatibilityMode => 'Network compatibility mode';
+  String get downloadNetworkCompatibilityMode => 'Netzwerkkompatibilitätsmodus';
 
   @override
   String get downloadNetworkCompatibilityModeEnabled =>
@@ -2948,7 +2979,7 @@ class AppLocalizationsDe extends AppLocalizations {
       'Append romanized lyrics when available';
 
   @override
-  String get downloadNeteaseIncludeRomanizationDisabled => 'Disabled';
+  String get downloadNeteaseIncludeRomanizationDisabled => 'Deaktiviert';
 
   @override
   String get downloadAppleQqMultiPerson => 'Apple/QQ Multi-Person Word-by-Word';
@@ -2980,10 +3011,10 @@ class AppLocalizationsDe extends AppLocalizations {
       'Keep full Album Artist metadata value';
 
   @override
-  String get downloadProvidersNoneEnabled => 'None enabled';
+  String get downloadProvidersNoneEnabled => 'Keine aktiviert';
 
   @override
-  String get downloadMusixmatchLanguageCode => 'Language code';
+  String get downloadMusixmatchLanguageCode => 'Sprach-Code';
 
   @override
   String get downloadMusixmatchLanguageHint => 'auto / en / es / ja';
@@ -2996,7 +3027,7 @@ class AppLocalizationsDe extends AppLocalizations {
   String get downloadMusixmatchAuto => 'Auto';
 
   @override
-  String get downloadNetworkAnySubtitle => 'WiFi + Mobile Data';
+  String get downloadNetworkAnySubtitle => 'WLAN + Mobile Daten';
 
   @override
   String get downloadNetworkWifiOnlySubtitle =>
@@ -3010,23 +3041,23 @@ class AppLocalizationsDe extends AppLocalizations {
   String get snackbarUnsupportedAudioFormat => 'Unsupported audio format';
 
   @override
-  String get cacheRefresh => 'Refresh';
+  String get cacheRefresh => 'Aktualisieren';
 
   @override
   String dialogDownloadPlaylistsMessage(int trackCount, int playlistCount) {
     String _temp0 = intl.Intl.pluralLogic(
       trackCount,
       locale: localeName,
-      other: 'tracks',
-      one: 'track',
+      other: 'Titel',
+      one: 'Titel',
     );
     String _temp1 = intl.Intl.pluralLogic(
       playlistCount,
       locale: localeName,
-      other: 'playlists',
-      one: 'playlist',
+      other: 'Playlists',
+      one: 'Playlist',
     );
-    return 'Download $trackCount $_temp0 from $playlistCount $_temp1?';
+    return 'Lade $trackCount $_temp0 von $playlistCount $_temp1?';
   }
 
   @override
@@ -3066,7 +3097,7 @@ class AppLocalizationsDe extends AppLocalizations {
       'Select fields to fill automatically from online metadata';
 
   @override
-  String get editMetadataAutoFillFetch => 'Fetch & Fill';
+  String get editMetadataAutoFillFetch => 'Abrufen & Ausfüllen';
 
   @override
   String get editMetadataAutoFillSearching => 'Searching online...';
@@ -3091,25 +3122,25 @@ class AppLocalizationsDe extends AppLocalizations {
       'Select at least one field to auto-fill';
 
   @override
-  String get editMetadataFieldTitle => 'Title';
+  String get editMetadataFieldTitle => 'Titel';
 
   @override
-  String get editMetadataFieldArtist => 'Artist';
+  String get editMetadataFieldArtist => 'Künstler';
 
   @override
   String get editMetadataFieldAlbum => 'Album';
 
   @override
-  String get editMetadataFieldAlbumArtist => 'Album Artist';
+  String get editMetadataFieldAlbumArtist => 'Album Künstler';
 
   @override
-  String get editMetadataFieldDate => 'Date';
+  String get editMetadataFieldDate => 'Datum';
 
   @override
-  String get editMetadataFieldTrackNum => 'Track #';
+  String get editMetadataFieldTrackNum => 'Titel #';
 
   @override
-  String get editMetadataFieldDiscNum => 'Disc #';
+  String get editMetadataFieldDiscNum => 'Disk #';
 
   @override
   String get editMetadataFieldGenre => 'Genre';
@@ -3121,16 +3152,16 @@ class AppLocalizationsDe extends AppLocalizations {
   String get editMetadataFieldLabel => 'Label';
 
   @override
-  String get editMetadataFieldCopyright => 'Copyright';
+  String get editMetadataFieldCopyright => 'Urheberrecht';
 
   @override
-  String get editMetadataFieldCover => 'Cover Art';
+  String get editMetadataFieldCover => 'Cover-Art';
 
   @override
-  String get editMetadataSelectAll => 'All';
+  String get editMetadataSelectAll => 'Alle';
 
   @override
-  String get editMetadataSelectEmpty => 'Empty only';
+  String get editMetadataSelectEmpty => 'Nur leer';
 
   @override
   String queueDownloadingCount(int count) {
@@ -3138,10 +3169,10 @@ class AppLocalizationsDe extends AppLocalizations {
   }
 
   @override
-  String get queueDownloadedHeader => 'Downloaded';
+  String get queueDownloadedHeader => 'Heruntergeladen';
 
   @override
-  String get queueFilteringIndicator => 'Filtering...';
+  String get queueFilteringIndicator => 'Filtere...';
 
   @override
   String queueTrackCount(int count) {
@@ -3166,7 +3197,7 @@ class AppLocalizationsDe extends AppLocalizations {
   }
 
   @override
-  String get queueEmptyAlbums => 'No album downloads';
+  String get queueEmptyAlbums => 'Keine Album-Downloads';
 
   @override
   String get queueEmptyAlbumsSubtitle =>
@@ -3192,7 +3223,7 @@ class AppLocalizationsDe extends AppLocalizations {
   String get selectionTapPlaylistsToSelect => 'Tap playlists to select';
 
   @override
-  String get selectionSelectPlaylistsToDelete => 'Select playlists to delete';
+  String get selectionSelectPlaylistsToDelete => 'Playlist zum Löschen wählen';
 
   @override
   String get audioAnalysisTitle => 'Audio Quality Analysis';
@@ -3202,37 +3233,37 @@ class AppLocalizationsDe extends AppLocalizations {
       'Verify lossless quality with spectrum analysis';
 
   @override
-  String get audioAnalysisAnalyzing => 'Analyzing audio...';
+  String get audioAnalysisAnalyzing => 'Audio wird analysiert...';
 
   @override
   String get audioAnalysisSampleRate => 'Sample Rate';
 
   @override
-  String get audioAnalysisBitDepth => 'Bit Depth';
+  String get audioAnalysisBitDepth => 'Bit-Tiefe';
 
   @override
-  String get audioAnalysisChannels => 'Channels';
+  String get audioAnalysisChannels => 'Kanäle';
 
   @override
-  String get audioAnalysisDuration => 'Duration';
+  String get audioAnalysisDuration => 'Länge';
 
   @override
   String get audioAnalysisNyquist => 'Nyquist';
 
   @override
-  String get audioAnalysisFileSize => 'Size';
+  String get audioAnalysisFileSize => 'Größe';
 
   @override
-  String get audioAnalysisDynamicRange => 'Dynamic Range';
+  String get audioAnalysisDynamicRange => 'Dynamischer Bereich';
 
   @override
-  String get audioAnalysisPeak => 'Peak';
+  String get audioAnalysisPeak => 'Maximum';
 
   @override
   String get audioAnalysisRms => 'RMS';
 
   @override
-  String get audioAnalysisSamples => 'Samples';
+  String get audioAnalysisSamples => 'Proben';
 
   @override
   String extensionsSearchWith(String providerName) {
@@ -3240,7 +3271,7 @@ class AppLocalizationsDe extends AppLocalizations {
   }
 
   @override
-  String get extensionsHomeFeedProvider => 'Home Feed Provider';
+  String get extensionsHomeFeedProvider => 'Home Feed Anbieter';
 
   @override
   String get extensionsHomeFeedDescription =>
@@ -3268,7 +3299,7 @@ class AppLocalizationsDe extends AppLocalizations {
   String get sortAlphaDesc => 'Z-A';
 
   @override
-  String get cancelDownloadTitle => 'Cancel download?';
+  String get cancelDownloadTitle => 'Download abbrechen?';
 
   @override
   String cancelDownloadContent(String trackName) {
@@ -3276,7 +3307,7 @@ class AppLocalizationsDe extends AppLocalizations {
   }
 
   @override
-  String get cancelDownloadKeep => 'Keep';
+  String get cancelDownloadKeep => 'Behalten';
 
   @override
   String get metadataSaveFailedFfmpeg => 'Failed to save metadata via FFmpeg';
@@ -3291,22 +3322,22 @@ class AppLocalizationsDe extends AppLocalizations {
   }
 
   @override
-  String get errorLoadAlbum => 'Failed to load album';
+  String get errorLoadAlbum => 'Fehler beim Laden des Albums';
 
   @override
-  String get errorLoadPlaylist => 'Failed to load playlist';
+  String get errorLoadPlaylist => 'Fehler beim Laden der Playlist';
 
   @override
-  String get errorLoadArtist => 'Failed to load artist';
+  String get errorLoadArtist => 'Fehler beim Laden des Interpreten';
 
   @override
-  String get notifChannelDownloadName => 'Download Progress';
+  String get notifChannelDownloadName => 'Download Fortschritt';
 
   @override
   String get notifChannelDownloadDesc => 'Shows download progress for tracks';
 
   @override
-  String get notifChannelLibraryScanName => 'Library Scan';
+  String get notifChannelLibraryScanName => 'Bibliotheksscan';
 
   @override
   String get notifChannelLibraryScanDesc => 'Shows local library scan progress';
@@ -3330,7 +3361,7 @@ class AppLocalizationsDe extends AppLocalizations {
   }
 
   @override
-  String get notifAlreadyInLibrary => 'Already in Library';
+  String get notifAlreadyInLibrary => 'Bereits in der Bibliothek';
 
   @override
   String notifDownloadCompleteCount(int completed, int total) {
@@ -3338,7 +3369,7 @@ class AppLocalizationsDe extends AppLocalizations {
   }
 
   @override
-  String get notifDownloadComplete => 'Download Complete';
+  String get notifDownloadComplete => 'Download abgeschlossen';
 
   @override
   String notifDownloadsFinished(int completed, int failed) {
@@ -3380,12 +3411,12 @@ class AppLocalizationsDe extends AppLocalizations {
 
   @override
   String notifLibraryScanExcluded(int count) {
-    return '$count excluded';
+    return '$count ausgeschlossen';
   }
 
   @override
   String notifLibraryScanErrors(int count) {
-    return '$count errors';
+    return '$count Fehler';
   }
 
   @override
@@ -3408,7 +3439,7 @@ class AppLocalizationsDe extends AppLocalizations {
   }
 
   @override
-  String get notifUpdateReady => 'Update Ready';
+  String get notifUpdateReady => 'Update bereit';
 
   @override
   String notifUpdateReadyBody(String version) {
@@ -3416,7 +3447,7 @@ class AppLocalizationsDe extends AppLocalizations {
   }
 
   @override
-  String get notifUpdateFailed => 'Update Failed';
+  String get notifUpdateFailed => 'Update fehlgeschlagen';
 
   @override
   String get notifUpdateFailedBody =>

lib/l10n/app_localizations_en.dart

@@ -127,6 +127,13 @@ class AppLocalizationsEn extends AppLocalizations {
     return 'Using extension: $extensionName';
   }
 
+  @override
+  String get optionsDefaultSearchTab => 'Default Search Tab';
+
+  @override
+  String get optionsDefaultSearchTabSubtitle =>
+      'Choose which tab opens first for new search results.';
+
   @override
   String get optionsSwitchBack =>
       'Tap Deezer or Spotify to switch back from extension';
@@ -334,6 +341,9 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get aboutPCSource => 'PC source code';
 
+  @override
+  String get aboutKeepAndroidOpen => 'Keep Android Open';
+
   @override
   String get aboutReportIssue => 'Report an issue';
 
@@ -926,6 +936,17 @@ class AppLocalizationsEn extends AppLocalizations {
   String get providerPriorityInfo =>
       'If a track is not available on the first provider, the app will automatically try the next one.';
 
+  @override
+  String get providerPriorityFallbackExtensionsTitle => 'Extension Fallback';
+
+  @override
+  String get providerPriorityFallbackExtensionsDescription =>
+      'Choose which installed download extensions can be used during automatic fallback. Built-in providers still follow the priority order above.';
+
+  @override
+  String get providerPriorityFallbackExtensionsHint =>
+      'Only enabled extensions with download-provider capability are listed here.';
+
   @override
   String get providerBuiltIn => 'Built-in';
 
@@ -1415,6 +1436,13 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get extensionsDownloadPrioritySubtitle => 'Set download service order';
 
+  @override
+  String get extensionsFallbackTitle => 'Fallback Extensions';
+
+  @override
+  String get extensionsFallbackSubtitle =>
+      'Choose which installed download extensions can be used as fallback';
+
   @override
   String get extensionsNoDownloadProvider =>
       'No extensions with download provider';

lib/l10n/app_localizations_fr.dart

@@ -21,13 +21,13 @@ class AppLocalizationsFr extends AppLocalizations {
   String get navSettings => 'Paramètres';
 
   @override
-  String get navStore => 'Magasin';
+  String get navStore => 'Repo';
 
   @override
   String get homeTitle => 'Accueil';
 
   @override
-  String get homeSubtitle => 'Coller un lien Spotify ou rechercher par nom';
+  String get homeSubtitle => 'Paste a supported URL or search by name';
 
   @override
   String get homeSupports => 'Supports: Piste, Album, Playlist, Artiste URLs';
@@ -128,6 +128,13 @@ class AppLocalizationsFr extends AppLocalizations {
     return 'Utilisation de l\'extension: $extensionName';
   }
 
+  @override
+  String get optionsDefaultSearchTab => 'Default Search Tab';
+
+  @override
+  String get optionsDefaultSearchTabSubtitle =>
+      'Choose which tab opens first for new search results.';
+
   @override
   String get optionsSwitchBack =>
       'Appuyez sur Deezer ou Spotify pour revenir à l\'extension';
@@ -211,10 +218,10 @@ class AppLocalizationsFr extends AppLocalizations {
       'Parallel downloads may trigger rate limiting';
 
   @override
-  String get optionsExtensionStore => 'Extension Store';
+  String get optionsExtensionStore => 'Extension Repo';
 
   @override
-  String get optionsExtensionStoreSubtitle => 'Show Store tab in navigation';
+  String get optionsExtensionStoreSubtitle => 'Show Repo tab in navigation';
 
   @override
   String get optionsCheckUpdates => 'Check for Updates';
@@ -275,7 +282,7 @@ class AppLocalizationsFr extends AppLocalizations {
   String get extensionsTitle => 'Extensions';
 
   @override
-  String get extensionsDisabled => 'Disabled';
+  String get extensionsDisabled => 'Désactivée';
 
   @override
   String extensionsVersion(String version) {
@@ -284,38 +291,38 @@ class AppLocalizationsFr extends AppLocalizations {
 
   @override
   String extensionsAuthor(String author) {
-    return 'by $author';
+    return 'par $author';
   }
 
   @override
   String get extensionsUninstall => 'Désinstaller';
 
   @override
-  String get storeTitle => 'Magasin d\'extension';
+  String get storeTitle => 'Extension Repo';
 
   @override
   String get storeSearch => 'Recherche d\'extensions...';
 
   @override
-  String get storeInstall => 'Install';
+  String get storeInstall => 'Installer';
 
   @override
-  String get storeInstalled => 'Installed';
+  String get storeInstalled => 'Installé';
 
   @override
-  String get storeUpdate => 'Update';
+  String get storeUpdate => 'Mettre à jour';
 
   @override
-  String get aboutTitle => 'About';
+  String get aboutTitle => 'À propos de';
 
   @override
-  String get aboutContributors => 'Contributors';
+  String get aboutContributors => 'Contributeurs';
 
   @override
-  String get aboutMobileDeveloper => 'Mobile version developer';
+  String get aboutMobileDeveloper => 'Développeur de la version mobile';
 
   @override
-  String get aboutOriginalCreator => 'Creator of the original SpotiFLAC';
+  String get aboutOriginalCreator => 'Créateur de SpotiFLAC original';
 
   @override
   String get aboutLogoArtist =>
@@ -336,6 +343,9 @@ class AppLocalizationsFr extends AppLocalizations {
   @override
   String get aboutPCSource => 'PC source code';
 
+  @override
+  String get aboutKeepAndroidOpen => 'Keep Android Open';
+
   @override
   String get aboutReportIssue => 'Report an issue';
 
@@ -352,7 +362,7 @@ class AppLocalizationsFr extends AppLocalizations {
   String get aboutTelegramChannel => 'Telegram Channel';
 
   @override
-  String get aboutTelegramChannelSubtitle => 'Announcements and updates';
+  String get aboutTelegramChannelSubtitle => 'Annonces et mises à jour';
 
   @override
   String get aboutTelegramChat => 'Telegram Community';
@@ -510,10 +520,11 @@ class AppLocalizationsFr extends AppLocalizations {
       'SpotiFLAC needs storage permission to save your downloaded music files.';
 
   @override
-  String get setupNotificationGranted => 'Notification Permission Granted!';
+  String get setupNotificationGranted =>
+      'Autorisation de notifications accordée!';
 
   @override
-  String get setupNotificationEnable => 'Enable Notifications';
+  String get setupNotificationEnable => 'Activer les notifications';
 
   @override
   String get setupFolderChoose => 'Choisissez le dossier pour télécharger';
@@ -523,39 +534,39 @@ class AppLocalizationsFr extends AppLocalizations {
       'Sélectionnez un dossier dans lequel votre musique téléchargée sera enregistrée.';
 
   @override
-  String get setupSelectFolder => 'Select Folder';
+  String get setupSelectFolder => 'Sélectionner un dossier';
 
   @override
-  String get setupEnableNotifications => 'Enable Notifications';
+  String get setupEnableNotifications => 'Activer les notifications';
 
   @override
   String get setupNotificationBackgroundDescription =>
       'Get notified about download progress and completion. This helps you track downloads when the app is in background.';
 
   @override
-  String get setupSkipForNow => 'Skip for now';
+  String get setupSkipForNow => 'Ignorer pour le moment';
 
   @override
-  String get setupNext => 'Next';
+  String get setupNext => 'Suivant';
 
   @override
-  String get setupGetStarted => 'Get Started';
+  String get setupGetStarted => 'Démarrer';
 
   @override
   String get setupAllowAccessToManageFiles =>
-      'Please enable \"Allow access to manage all files\" in the next screen.';
+      'Veuillez activer \"Autoriser l\'accès à tous les fichiers\" sur l\'écran suivant.';
 
   @override
-  String get dialogCancel => 'Cancel';
+  String get dialogCancel => 'Annuler';
 
   @override
-  String get dialogSave => 'Save';
+  String get dialogSave => 'Sauvegarder';
 
   @override
-  String get dialogDelete => 'Delete';
+  String get dialogDelete => 'Supprimer';
 
   @override
-  String get dialogRetry => 'Retry';
+  String get dialogRetry => 'Réessayer';
 
   @override
   String get dialogClear => 'Clear';
@@ -567,7 +578,7 @@ class AppLocalizationsFr extends AppLocalizations {
   String get dialogImport => 'Import';
 
   @override
-  String get dialogDownload => 'Download';
+  String get dialogDownload => 'Télécharger';
 
   @override
   String get dialogDiscard => 'Discard';
@@ -576,10 +587,10 @@ class AppLocalizationsFr extends AppLocalizations {
   String get dialogRemove => 'Remove';
 
   @override
-  String get dialogUninstall => 'Uninstall';
+  String get dialogUninstall => 'Désinstaller';
 
   @override
-  String get dialogDiscardChanges => 'Discard Changes?';
+  String get dialogDiscardChanges => 'Ignorer les modifications ?';
 
   @override
   String get dialogUnsavedChanges =>
@@ -928,6 +939,17 @@ class AppLocalizationsFr extends AppLocalizations {
   String get providerPriorityInfo =>
       'If a track is not available on the first provider, the app will automatically try the next one.';
 
+  @override
+  String get providerPriorityFallbackExtensionsTitle => 'Extension Fallback';
+
+  @override
+  String get providerPriorityFallbackExtensionsDescription =>
+      'Choose which installed download extensions can be used during automatic fallback. Built-in providers still follow the priority order above.';
+
+  @override
+  String get providerPriorityFallbackExtensionsHint =>
+      'Only enabled extensions with download-provider capability are listed here.';
+
   @override
   String get providerBuiltIn => 'Built-in';
 
@@ -1317,7 +1339,7 @@ class AppLocalizationsFr extends AppLocalizations {
   String get storeEmptyNoResults => 'No extensions found';
 
   @override
-  String get extensionDefaultProvider => 'Default (Deezer/Spotify)';
+  String get extensionDefaultProvider => 'Default (Deezer)';
 
   @override
   String get extensionDefaultProviderSubtitle => 'Use built-in search';
@@ -1417,6 +1439,13 @@ class AppLocalizationsFr extends AppLocalizations {
   @override
   String get extensionsDownloadPrioritySubtitle => 'Set download service order';
 
+  @override
+  String get extensionsFallbackTitle => 'Fallback Extensions';
+
+  @override
+  String get extensionsFallbackSubtitle =>
+      'Choose which installed download extensions can be used as fallback';
+
   @override
   String get extensionsNoDownloadProvider =>
       'No extensions with download provider';
@@ -2088,7 +2117,7 @@ class AppLocalizationsFr extends AppLocalizations {
 
   @override
   String get tutorialExtensionsTip1 =>
-      'Browse the Store tab to discover useful extensions';
+      'Browse the Repo tab to discover useful extensions';
 
   @override
   String get tutorialExtensionsTip2 =>
@@ -2369,7 +2398,8 @@ class AppLocalizationsFr extends AppLocalizations {
   String get trackConvertFormat => 'Convert Format';
 
   @override
-  String get trackConvertFormatSubtitle => 'Convert to MP3 or Opus';
+  String get trackConvertFormatSubtitle =>
+      'Convert to MP3, Opus, ALAC, or FLAC';
 
   @override
   String get trackConvertTitle => 'Convert Audio';

lib/l10n/app_localizations_hi.dart

@@ -21,13 +21,13 @@ class AppLocalizationsHi extends AppLocalizations {
   String get navSettings => 'विकल्प';
 
   @override
-  String get navStore => 'Store';
+  String get navStore => 'Repo';
 
   @override
   String get homeTitle => 'Home';
 
   @override
-  String get homeSubtitle => 'Paste a Spotify link or search by name';
+  String get homeSubtitle => 'Paste a supported URL or search by name';
 
   @override
   String get homeSupports => 'Supports: Track, Album, Playlist, Artist URLs';
@@ -127,6 +127,13 @@ class AppLocalizationsHi extends AppLocalizations {
     return 'Using extension: $extensionName';
   }
 
+  @override
+  String get optionsDefaultSearchTab => 'Default Search Tab';
+
+  @override
+  String get optionsDefaultSearchTabSubtitle =>
+      'Choose which tab opens first for new search results.';
+
   @override
   String get optionsSwitchBack =>
       'Tap Deezer or Spotify to switch back from extension';
@@ -209,10 +216,10 @@ class AppLocalizationsHi extends AppLocalizations {
       'Parallel downloads may trigger rate limiting';
 
   @override
-  String get optionsExtensionStore => 'Extension Store';
+  String get optionsExtensionStore => 'Extension Repo';
 
   @override
-  String get optionsExtensionStoreSubtitle => 'Show Store tab in navigation';
+  String get optionsExtensionStoreSubtitle => 'Show Repo tab in navigation';
 
   @override
   String get optionsCheckUpdates => 'Check for Updates';
@@ -289,7 +296,7 @@ class AppLocalizationsHi extends AppLocalizations {
   String get extensionsUninstall => 'Uninstall';
 
   @override
-  String get storeTitle => 'Extension Store';
+  String get storeTitle => 'Extension Repo';
 
   @override
   String get storeSearch => 'Search extensions...';
@@ -334,6 +341,9 @@ class AppLocalizationsHi extends AppLocalizations {
   @override
   String get aboutPCSource => 'PC source code';
 
+  @override
+  String get aboutKeepAndroidOpen => 'Keep Android Open';
+
   @override
   String get aboutReportIssue => 'Report an issue';
 
@@ -926,6 +936,17 @@ class AppLocalizationsHi extends AppLocalizations {
   String get providerPriorityInfo =>
       'If a track is not available on the first provider, the app will automatically try the next one.';
 
+  @override
+  String get providerPriorityFallbackExtensionsTitle => 'Extension Fallback';
+
+  @override
+  String get providerPriorityFallbackExtensionsDescription =>
+      'Choose which installed download extensions can be used during automatic fallback. Built-in providers still follow the priority order above.';
+
+  @override
+  String get providerPriorityFallbackExtensionsHint =>
+      'Only enabled extensions with download-provider capability are listed here.';
+
   @override
   String get providerBuiltIn => 'Built-in';
 
@@ -1315,7 +1336,7 @@ class AppLocalizationsHi extends AppLocalizations {
   String get storeEmptyNoResults => 'No extensions found';
 
   @override
-  String get extensionDefaultProvider => 'Default (Deezer/Spotify)';
+  String get extensionDefaultProvider => 'Default (Deezer)';
 
   @override
   String get extensionDefaultProviderSubtitle => 'Use built-in search';
@@ -1415,6 +1436,13 @@ class AppLocalizationsHi extends AppLocalizations {
   @override
   String get extensionsDownloadPrioritySubtitle => 'Set download service order';
 
+  @override
+  String get extensionsFallbackTitle => 'Fallback Extensions';
+
+  @override
+  String get extensionsFallbackSubtitle =>
+      'Choose which installed download extensions can be used as fallback';
+
   @override
   String get extensionsNoDownloadProvider =>
       'No extensions with download provider';
@@ -2086,7 +2114,7 @@ class AppLocalizationsHi extends AppLocalizations {
 
   @override
   String get tutorialExtensionsTip1 =>
-      'Browse the Store tab to discover useful extensions';
+      'Browse the Repo tab to discover useful extensions';
 
   @override
   String get tutorialExtensionsTip2 =>
@@ -2367,7 +2395,8 @@ class AppLocalizationsHi extends AppLocalizations {
   String get trackConvertFormat => 'Convert Format';
 
   @override
-  String get trackConvertFormatSubtitle => 'Convert to MP3 or Opus';
+  String get trackConvertFormatSubtitle =>
+      'Convert to MP3, Opus, ALAC, or FLAC';
 
   @override
   String get trackConvertTitle => 'Convert Audio';

lib/l10n/app_localizations_id.dart

@@ -27,8 +27,7 @@ class AppLocalizationsId extends AppLocalizations {
   String get homeTitle => 'Beranda';
 
   @override
-  String get homeSubtitle =>
-      'Tempel URL yang didukung atau cari berdasarkan nama';
+  String get homeSubtitle => 'Paste a supported URL or search by name';
 
   @override
   String get homeSupports => 'Mendukung: URL Track, Album, Playlist, Artis';
@@ -129,6 +128,13 @@ class AppLocalizationsId extends AppLocalizations {
     return 'Menggunakan ekstensi: $extensionName';
   }
 
+  @override
+  String get optionsDefaultSearchTab => 'Default Search Tab';
+
+  @override
+  String get optionsDefaultSearchTabSubtitle =>
+      'Choose which tab opens first for new search results.';
+
   @override
   String get optionsSwitchBack =>
       'Ketuk Deezer atau Spotify untuk beralih dari ekstensi';
@@ -213,10 +219,10 @@ class AppLocalizationsId extends AppLocalizations {
       'Unduhan paralel dapat memicu pembatasan rate';
 
   @override
-  String get optionsExtensionStore => 'Repo Ekstensi';
+  String get optionsExtensionStore => 'Extension Repo';
 
   @override
-  String get optionsExtensionStoreSubtitle => 'Tampilkan tab Repo di navigasi';
+  String get optionsExtensionStoreSubtitle => 'Show Repo tab in navigation';
 
   @override
   String get optionsCheckUpdates => 'Periksa Pembaruan';
@@ -292,7 +298,7 @@ class AppLocalizationsId extends AppLocalizations {
   String get extensionsUninstall => 'Copot';
 
   @override
-  String get storeTitle => 'Repo Ekstensi';
+  String get storeTitle => 'Extension Repo';
 
   @override
   String get storeSearch => 'Cari ekstensi...';
@@ -337,6 +343,9 @@ class AppLocalizationsId extends AppLocalizations {
   @override
   String get aboutPCSource => 'Kode sumber PC';
 
+  @override
+  String get aboutKeepAndroidOpen => 'Keep Android Open';
+
   @override
   String get aboutReportIssue => 'Laporkan masalah';
 
@@ -735,15 +744,15 @@ class AppLocalizationsId extends AppLocalizations {
   String get errorNoTracksFound => 'Tidak ada lagu ditemukan';
 
   @override
-  String get errorUrlNotRecognized => 'Link tidak dikenali';
+  String get errorUrlNotRecognized => 'Tautan tidak dikenali';
 
   @override
   String get errorUrlNotRecognizedMessage =>
-      'Link ini tidak didukung. Pastikan URL benar dan ekstensi yang kompatibel sudah terpasang.';
+      'Tautan ini tidak didukung. Pastikan URL sudah benar dan ekstensi yang kompatibel telah terpasang.';
 
   @override
   String get errorUrlFetchFailed =>
-      'Gagal memuat konten dari link ini. Silakan coba lagi.';
+      'Konten dari tautan ini gagal dimuat. Silakan coba lagi.';
 
   @override
   String errorMissingExtensionSource(String item) {
@@ -930,6 +939,17 @@ class AppLocalizationsId extends AppLocalizations {
   String get providerPriorityInfo =>
       'Jika lagu tidak tersedia di provider pertama, aplikasi akan otomatis mencoba yang berikutnya.';
 
+  @override
+  String get providerPriorityFallbackExtensionsTitle => 'Extension Fallback';
+
+  @override
+  String get providerPriorityFallbackExtensionsDescription =>
+      'Choose which installed download extensions can be used during automatic fallback. Built-in providers still follow the priority order above.';
+
+  @override
+  String get providerPriorityFallbackExtensionsHint =>
+      'Only enabled extensions with download-provider capability are listed here.';
+
   @override
   String get providerBuiltIn => 'Bawaan';
 
@@ -1313,7 +1333,7 @@ class AppLocalizationsId extends AppLocalizations {
   String get storeNewRepoUrlLabel => 'New Repository URL';
 
   @override
-  String get storeLoadError => 'Gagal memuat repo';
+  String get storeLoadError => 'Failed to load repository';
 
   @override
   String get storeEmptyNoExtensions => 'No extensions available';
@@ -1322,7 +1342,7 @@ class AppLocalizationsId extends AppLocalizations {
   String get storeEmptyNoResults => 'No extensions found';
 
   @override
-  String get extensionDefaultProvider => 'Bawaan (Deezer/Spotify)';
+  String get extensionDefaultProvider => 'Default (Deezer)';
 
   @override
   String get extensionDefaultProviderSubtitle => 'Gunakan pencarian bawaan';
@@ -1423,6 +1443,13 @@ class AppLocalizationsId extends AppLocalizations {
   String get extensionsDownloadPrioritySubtitle =>
       'Atur urutan layanan unduhan';
 
+  @override
+  String get extensionsFallbackTitle => 'Fallback Extensions';
+
+  @override
+  String get extensionsFallbackSubtitle =>
+      'Choose which installed download extensions can be used as fallback';
+
   @override
   String get extensionsNoDownloadProvider =>
       'Tidak ada ekstensi dengan provider unduhan';
@@ -2096,7 +2123,7 @@ class AppLocalizationsId extends AppLocalizations {
 
   @override
   String get tutorialExtensionsTip1 =>
-      'Buka tab Repo untuk menemukan ekstensi yang berguna';
+      'Browse the Repo tab to discover useful extensions';
 
   @override
   String get tutorialExtensionsTip2 =>
@@ -2347,25 +2374,25 @@ class AppLocalizationsId extends AppLocalizations {
   String get trackReEnrichFfmpegFailed => 'FFmpeg metadata embed failed';
 
   @override
-  String get queueFlacAction => 'Antrekan FLAC';
+  String get queueFlacAction => 'Queue FLAC';
 
   @override
   String queueFlacConfirmMessage(int count) {
-    return 'Cari kecocokan online untuk track yang dipilih lalu antrekan download FLAC.\n\nFile yang sudah ada tidak akan diubah atau dihapus.\n\nHanya kecocokan dengan keyakinan tinggi yang akan diantrikan otomatis.\n\n$count dipilih';
+    return 'Search online matches for the selected tracks and queue FLAC downloads.\n\nExisting files will not be modified or deleted.\n\nOnly high-confidence matches are queued automatically.\n\n$count selected';
   }
 
   @override
   String queueFlacFindingProgress(int current, int total) {
-    return 'Mencari kecocokan FLAC... ($current/$total)';
+    return 'Finding FLAC matches... ($current/$total)';
   }
 
   @override
   String get queueFlacNoReliableMatches =>
-      'Tidak ada kecocokan online yang cukup meyakinkan untuk pilihan ini';
+      'No reliable online matches found for the selection';
 
   @override
   String queueFlacQueuedWithSkipped(int addedCount, int skippedCount) {
-    return 'Menambahkan $addedCount track ke antrean, melewati $skippedCount';
+    return 'Added $addedCount tracks to queue, skipped $skippedCount';
   }
 
   @override
@@ -2378,7 +2405,7 @@ class AppLocalizationsId extends AppLocalizations {
 
   @override
   String get trackConvertFormatSubtitle =>
-      'Konversi ke MP3, Opus, ALAC, atau FLAC';
+      'Convert to MP3, Opus, ALAC, or FLAC';
 
   @override
   String get trackConvertTitle => 'Convert Audio';
@@ -2406,12 +2433,12 @@ class AppLocalizationsId extends AppLocalizations {
     String sourceFormat,
     String targetFormat,
   ) {
-    return 'Konversi dari $sourceFormat ke $targetFormat? (Lossless — tanpa kehilangan kualitas)\n\nFile asli akan dihapus setelah konversi.';
+    return 'Convert from $sourceFormat to $targetFormat? (Lossless — no quality loss)\n\nThe original file will be deleted after conversion.';
   }
 
   @override
   String get trackConvertLosslessHint =>
-      'Konversi lossless — tanpa kehilangan kualitas';
+      'Lossless conversion — no quality loss';
 
   @override
   String get trackConvertConverting => 'Converting audio...';
@@ -2865,19 +2892,19 @@ class AppLocalizationsId extends AppLocalizations {
 
   @override
   String get downloadCreatePlaylistSourceFolder =>
-      'Buat folder sumber playlist';
+      'Create playlist source folder';
 
   @override
   String get downloadCreatePlaylistSourceFolderEnabled =>
-      'Unduhan dari playlist memakai Playlist/ lalu struktur folder normal Anda.';
+      'Playlist downloads use Playlist/ plus your normal folder structure.';
 
   @override
   String get downloadCreatePlaylistSourceFolderDisabled =>
-      'Unduhan dari playlist hanya memakai struktur folder normal.';
+      'Playlist downloads use the normal folder structure only.';
 
   @override
   String get downloadCreatePlaylistSourceFolderRedundant =>
-      'Mode Berdasarkan Playlist sudah menaruh unduhan ke dalam folder playlist.';
+      'By Playlist already places downloads inside a playlist folder.';
 
   @override
   String get downloadSongLinkRegion => 'SongLink Region';

lib/l10n/app_localizations_ja.dart

@@ -21,13 +21,13 @@ class AppLocalizationsJa extends AppLocalizations {
   String get navSettings => '設定';
 
   @override
-  String get navStore => 'ストア';
+  String get navStore => 'Repo';
 
   @override
   String get homeTitle => 'ホーム';
 
   @override
-  String get homeSubtitle => 'Spotify のリンクを貼り付けるか、名前で検索します';
+  String get homeSubtitle => 'Paste a supported URL or search by name';
 
   @override
   String get homeSupports => 'サポート: トラック、アルバム、プレイリスト、アーティスト、URL';
@@ -127,6 +127,13 @@ class AppLocalizationsJa extends AppLocalizations {
     return '拡張の使用: $extensionName';
   }
 
+  @override
+  String get optionsDefaultSearchTab => 'Default Search Tab';
+
+  @override
+  String get optionsDefaultSearchTabSubtitle =>
+      'Choose which tab opens first for new search results.';
+
   @override
   String get optionsSwitchBack =>
       'Tap Deezer or Spotify to switch back from extension';
@@ -207,10 +214,10 @@ class AppLocalizationsJa extends AppLocalizations {
       'Parallel downloads may trigger rate limiting';
 
   @override
-  String get optionsExtensionStore => '拡張ストア';
+  String get optionsExtensionStore => 'Extension Repo';
 
   @override
-  String get optionsExtensionStoreSubtitle => 'ナビゲーションにストアタブを表示';
+  String get optionsExtensionStoreSubtitle => 'Show Repo tab in navigation';
 
   @override
   String get optionsCheckUpdates => '更新を確認';
@@ -286,7 +293,7 @@ class AppLocalizationsJa extends AppLocalizations {
   String get extensionsUninstall => 'アンインストール';
 
   @override
-  String get storeTitle => '拡張ストア';
+  String get storeTitle => 'Extension Repo';
 
   @override
   String get storeSearch => '拡張を検索...';
@@ -330,6 +337,9 @@ class AppLocalizationsJa extends AppLocalizations {
   @override
   String get aboutPCSource => 'PC 版のソースコード';
 
+  @override
+  String get aboutKeepAndroidOpen => 'Keep Android Open';
+
   @override
   String get aboutReportIssue => '問題を報告する';
 
@@ -920,6 +930,17 @@ class AppLocalizationsJa extends AppLocalizations {
   String get providerPriorityInfo =>
       'If a track is not available on the first provider, the app will automatically try the next one.';
 
+  @override
+  String get providerPriorityFallbackExtensionsTitle => 'Extension Fallback';
+
+  @override
+  String get providerPriorityFallbackExtensionsDescription =>
+      'Choose which installed download extensions can be used during automatic fallback. Built-in providers still follow the priority order above.';
+
+  @override
+  String get providerPriorityFallbackExtensionsHint =>
+      'Only enabled extensions with download-provider capability are listed here.';
+
   @override
   String get providerBuiltIn => '内蔵';
 
@@ -1309,7 +1330,7 @@ class AppLocalizationsJa extends AppLocalizations {
   String get storeEmptyNoResults => 'No extensions found';
 
   @override
-  String get extensionDefaultProvider => 'デフォルト (Deezer/Spotify)';
+  String get extensionDefaultProvider => 'Default (Deezer)';
 
   @override
   String get extensionDefaultProviderSubtitle => '内蔵の検索を使用する';
@@ -1409,6 +1430,13 @@ class AppLocalizationsJa extends AppLocalizations {
   @override
   String get extensionsDownloadPrioritySubtitle => 'ダウンロードサービスの順序を設定';
 
+  @override
+  String get extensionsFallbackTitle => 'Fallback Extensions';
+
+  @override
+  String get extensionsFallbackSubtitle =>
+      'Choose which installed download extensions can be used as fallback';
+
   @override
   String get extensionsNoDownloadProvider => 'ダウンロードプロバイダーの拡張はありません';
 
@@ -2073,7 +2101,7 @@ class AppLocalizationsJa extends AppLocalizations {
 
   @override
   String get tutorialExtensionsTip1 =>
-      'Browse the Store tab to discover useful extensions';
+      'Browse the Repo tab to discover useful extensions';
 
   @override
   String get tutorialExtensionsTip2 =>
@@ -2354,7 +2382,8 @@ class AppLocalizationsJa extends AppLocalizations {
   String get trackConvertFormat => '変換の形式';
 
   @override
-  String get trackConvertFormatSubtitle => 'MP3 または Opus に変換';
+  String get trackConvertFormatSubtitle =>
+      'Convert to MP3, Opus, ALAC, or FLAC';
 
   @override
   String get trackConvertTitle => 'オーディオを変換';

lib/l10n/app_localizations_ko.dart

@@ -21,13 +21,13 @@ class AppLocalizationsKo extends AppLocalizations {
   String get navSettings => 'Settings';
 
   @override
-  String get navStore => 'Store';
+  String get navStore => 'Repo';
 
   @override
   String get homeTitle => 'Home';
 
   @override
-  String get homeSubtitle => 'Spotify URL을 붙여 넣거나 검색';
+  String get homeSubtitle => 'Paste a supported URL or search by name';
 
   @override
   String get homeSupports => '지원 항목: 트랙, 앨범, 플레이리스트, 아티스트 URLs';
@@ -125,6 +125,13 @@ class AppLocalizationsKo extends AppLocalizations {
     return '확장 기능을 사용: $extensionName';
   }
 
+  @override
+  String get optionsDefaultSearchTab => 'Default Search Tab';
+
+  @override
+  String get optionsDefaultSearchTabSubtitle =>
+      'Choose which tab opens first for new search results.';
+
   @override
   String get optionsSwitchBack => 'Deezer 또는 Spotify를 탭하여 확장 기능에서 다시 전환하세요.';
 
@@ -202,10 +209,10 @@ class AppLocalizationsKo extends AppLocalizations {
   String get optionsConcurrentWarning => '동시에 다수의 음반을 다운로드하면 속도 제한이 발생할 수 있습니다';
 
   @override
-  String get optionsExtensionStore => '확장 기능 스토어';
+  String get optionsExtensionStore => 'Extension Repo';
 
   @override
-  String get optionsExtensionStoreSubtitle => '탐색 메뉴에 스토어 탭 표시';
+  String get optionsExtensionStoreSubtitle => 'Show Repo tab in navigation';
 
   @override
   String get optionsCheckUpdates => '업데이트 확인';
@@ -279,7 +286,7 @@ class AppLocalizationsKo extends AppLocalizations {
   String get extensionsUninstall => '삭제';
 
   @override
-  String get storeTitle => '확장 기능 스토어';
+  String get storeTitle => 'Extension Repo';
 
   @override
   String get storeSearch => '확장 기능 검색';
@@ -323,6 +330,9 @@ class AppLocalizationsKo extends AppLocalizations {
   @override
   String get aboutPCSource => 'PC 소스 코드';
 
+  @override
+  String get aboutKeepAndroidOpen => 'Keep Android Open';
+
   @override
   String get aboutReportIssue => '문제 신고';
 
@@ -908,6 +918,17 @@ class AppLocalizationsKo extends AppLocalizations {
   String get providerPriorityInfo =>
       'If a track is not available on the first provider, the app will automatically try the next one.';
 
+  @override
+  String get providerPriorityFallbackExtensionsTitle => 'Extension Fallback';
+
+  @override
+  String get providerPriorityFallbackExtensionsDescription =>
+      'Choose which installed download extensions can be used during automatic fallback. Built-in providers still follow the priority order above.';
+
+  @override
+  String get providerPriorityFallbackExtensionsHint =>
+      'Only enabled extensions with download-provider capability are listed here.';
+
   @override
   String get providerBuiltIn => 'Built-in';
 
@@ -1295,7 +1316,7 @@ class AppLocalizationsKo extends AppLocalizations {
   String get storeEmptyNoResults => 'No extensions found';
 
   @override
-  String get extensionDefaultProvider => 'Default (Deezer/Spotify)';
+  String get extensionDefaultProvider => 'Default (Deezer)';
 
   @override
   String get extensionDefaultProviderSubtitle => 'Use built-in search';
@@ -1395,6 +1416,13 @@ class AppLocalizationsKo extends AppLocalizations {
   @override
   String get extensionsDownloadPrioritySubtitle => 'Set download service order';
 
+  @override
+  String get extensionsFallbackTitle => 'Fallback Extensions';
+
+  @override
+  String get extensionsFallbackSubtitle =>
+      'Choose which installed download extensions can be used as fallback';
+
   @override
   String get extensionsNoDownloadProvider =>
       'No extensions with download provider';
@@ -2066,7 +2094,7 @@ class AppLocalizationsKo extends AppLocalizations {
 
   @override
   String get tutorialExtensionsTip1 =>
-      'Browse the Store tab to discover useful extensions';
+      'Browse the Repo tab to discover useful extensions';
 
   @override
   String get tutorialExtensionsTip2 =>
@@ -2347,7 +2375,8 @@ class AppLocalizationsKo extends AppLocalizations {
   String get trackConvertFormat => 'Convert Format';
 
   @override
-  String get trackConvertFormatSubtitle => 'Convert to MP3 or Opus';
+  String get trackConvertFormatSubtitle =>
+      'Convert to MP3, Opus, ALAC, or FLAC';
 
   @override
   String get trackConvertTitle => 'Convert Audio';

lib/l10n/app_localizations_nl.dart

@@ -21,13 +21,13 @@ class AppLocalizationsNl extends AppLocalizations {
   String get navSettings => 'Settings';
 
   @override
-  String get navStore => 'Store';
+  String get navStore => 'Repo';
 
   @override
   String get homeTitle => 'Home';
 
   @override
-  String get homeSubtitle => 'Paste a Spotify link or search by name';
+  String get homeSubtitle => 'Paste a supported URL or search by name';
 
   @override
   String get homeSupports => 'Supports: Track, Album, Playlist, Artist URLs';
@@ -127,6 +127,13 @@ class AppLocalizationsNl extends AppLocalizations {
     return 'Using extension: $extensionName';
   }
 
+  @override
+  String get optionsDefaultSearchTab => 'Default Search Tab';
+
+  @override
+  String get optionsDefaultSearchTabSubtitle =>
+      'Choose which tab opens first for new search results.';
+
   @override
   String get optionsSwitchBack =>
       'Tap Deezer or Spotify to switch back from extension';
@@ -209,10 +216,10 @@ class AppLocalizationsNl extends AppLocalizations {
       'Parallel downloaden kan leiden tot rate-limiting';
 
   @override
-  String get optionsExtensionStore => 'Extension Store';
+  String get optionsExtensionStore => 'Extension Repo';
 
   @override
-  String get optionsExtensionStoreSubtitle => 'Show Store tab in navigation';
+  String get optionsExtensionStoreSubtitle => 'Show Repo tab in navigation';
 
   @override
   String get optionsCheckUpdates => 'Check for Updates';
@@ -289,7 +296,7 @@ class AppLocalizationsNl extends AppLocalizations {
   String get extensionsUninstall => 'Uninstall';
 
   @override
-  String get storeTitle => 'Extension Store';
+  String get storeTitle => 'Extension Repo';
 
   @override
   String get storeSearch => 'Search extensions...';
@@ -334,6 +341,9 @@ class AppLocalizationsNl extends AppLocalizations {
   @override
   String get aboutPCSource => 'PC source code';
 
+  @override
+  String get aboutKeepAndroidOpen => 'Keep Android Open';
+
   @override
   String get aboutReportIssue => 'Report an issue';
 
@@ -926,6 +936,17 @@ class AppLocalizationsNl extends AppLocalizations {
   String get providerPriorityInfo =>
       'If a track is not available on the first provider, the app will automatically try the next one.';
 
+  @override
+  String get providerPriorityFallbackExtensionsTitle => 'Extension Fallback';
+
+  @override
+  String get providerPriorityFallbackExtensionsDescription =>
+      'Choose which installed download extensions can be used during automatic fallback. Built-in providers still follow the priority order above.';
+
+  @override
+  String get providerPriorityFallbackExtensionsHint =>
+      'Only enabled extensions with download-provider capability are listed here.';
+
   @override
   String get providerBuiltIn => 'Built-in';
 
@@ -1315,7 +1336,7 @@ class AppLocalizationsNl extends AppLocalizations {
   String get storeEmptyNoResults => 'No extensions found';
 
   @override
-  String get extensionDefaultProvider => 'Default (Deezer/Spotify)';
+  String get extensionDefaultProvider => 'Default (Deezer)';
 
   @override
   String get extensionDefaultProviderSubtitle => 'Use built-in search';
@@ -1415,6 +1436,13 @@ class AppLocalizationsNl extends AppLocalizations {
   @override
   String get extensionsDownloadPrioritySubtitle => 'Set download service order';
 
+  @override
+  String get extensionsFallbackTitle => 'Fallback Extensions';
+
+  @override
+  String get extensionsFallbackSubtitle =>
+      'Choose which installed download extensions can be used as fallback';
+
   @override
   String get extensionsNoDownloadProvider =>
       'No extensions with download provider';
@@ -2086,7 +2114,7 @@ class AppLocalizationsNl extends AppLocalizations {
 
   @override
   String get tutorialExtensionsTip1 =>
-      'Browse the Store tab to discover useful extensions';
+      'Browse the Repo tab to discover useful extensions';
 
   @override
   String get tutorialExtensionsTip2 =>
@@ -2367,7 +2395,8 @@ class AppLocalizationsNl extends AppLocalizations {
   String get trackConvertFormat => 'Convert Format';
 
   @override
-  String get trackConvertFormatSubtitle => 'Convert to MP3 or Opus';
+  String get trackConvertFormatSubtitle =>
+      'Convert to MP3, Opus, ALAC, or FLAC';
 
   @override
   String get trackConvertTitle => 'Convert Audio';

lib/l10n/app_localizations_ru.dart

@@ -21,13 +21,13 @@ class AppLocalizationsRu extends AppLocalizations {
   String get navSettings => 'Настройки';
 
   @override
-  String get navStore => 'Магазин';
+  String get navStore => 'Repo';
 
   @override
   String get homeTitle => 'Главная';
 
   @override
-  String get homeSubtitle => 'Вставьте ссылку Spotify или ищите по названию';
+  String get homeSubtitle => 'Paste a supported URL or search by name';
 
   @override
   String get homeSupports =>
@@ -129,6 +129,13 @@ class AppLocalizationsRu extends AppLocalizations {
     return 'Используется расширение: $extensionName';
   }
 
+  @override
+  String get optionsDefaultSearchTab => 'Default Search Tab';
+
+  @override
+  String get optionsDefaultSearchTabSubtitle =>
+      'Choose which tab opens first for new search results.';
+
   @override
   String get optionsSwitchBack =>
       'Нажмите Deezer или Spotify для возврата с расширения';
@@ -214,11 +221,10 @@ class AppLocalizationsRu extends AppLocalizations {
       'Параллельные загрузки могут вызвать ограничение скорости';
 
   @override
-  String get optionsExtensionStore => 'Магазин расширений';
+  String get optionsExtensionStore => 'Extension Repo';
 
   @override
-  String get optionsExtensionStoreSubtitle =>
-      'Показывать вкладку Магазин в гл. меню';
+  String get optionsExtensionStoreSubtitle => 'Show Repo tab in navigation';
 
   @override
   String get optionsCheckUpdates => 'Проверить обновления';
@@ -295,7 +301,7 @@ class AppLocalizationsRu extends AppLocalizations {
   String get extensionsUninstall => 'Удалить';
 
   @override
-  String get storeTitle => 'Магазин расширений';
+  String get storeTitle => 'Extension Repo';
 
   @override
   String get storeSearch => 'Поиск расширений...';
@@ -340,6 +346,9 @@ class AppLocalizationsRu extends AppLocalizations {
   @override
   String get aboutPCSource => 'Исходный код ПК версии';
 
+  @override
+  String get aboutKeepAndroidOpen => 'Keep Android Open';
+
   @override
   String get aboutReportIssue => 'Сообщить о проблеме';
 
@@ -626,9 +635,9 @@ class AppLocalizationsRu extends AppLocalizations {
       count,
       locale: localeName,
       other: 'треков',
+      one: 'трек',
       many: 'треков',
       few: 'трека',
-      one: 'трек',
     );
     return 'Удалить $count $_temp0 из истории?\n\nЭто также удалит файлы из хранилища.';
   }
@@ -681,9 +690,9 @@ class AppLocalizationsRu extends AppLocalizations {
       count,
       locale: localeName,
       other: 'треков',
+      one: 'трек',
       many: 'треков',
       few: 'трека',
-      one: 'трек',
     );
     return 'Удалено $count $_temp0';
   }
@@ -940,6 +949,17 @@ class AppLocalizationsRu extends AppLocalizations {
   String get providerPriorityInfo =>
       'Если трек не доступен у первого провайдера, приложение автоматически попробует следующий.';
 
+  @override
+  String get providerPriorityFallbackExtensionsTitle => 'Extension Fallback';
+
+  @override
+  String get providerPriorityFallbackExtensionsDescription =>
+      'Choose which installed download extensions can be used during automatic fallback. Built-in providers still follow the priority order above.';
+
+  @override
+  String get providerPriorityFallbackExtensionsHint =>
+      'Only enabled extensions with download-provider capability are listed here.';
+
   @override
   String get providerBuiltIn => 'Встроенные';
 
@@ -1140,9 +1160,9 @@ class AppLocalizationsRu extends AppLocalizations {
       count,
       locale: localeName,
       other: '$count треков',
+      one: '1 трек',
       many: '$count треков',
       few: '$count трека',
-      one: '$count трек',
     );
     return '$_temp0';
   }
@@ -1336,7 +1356,7 @@ class AppLocalizationsRu extends AppLocalizations {
   String get storeEmptyNoResults => 'No extensions found';
 
   @override
-  String get extensionDefaultProvider => 'По умолчанию (Deezer/Spotify)';
+  String get extensionDefaultProvider => 'Default (Deezer)';
 
   @override
   String get extensionDefaultProviderSubtitle =>
@@ -1439,6 +1459,13 @@ class AppLocalizationsRu extends AppLocalizations {
   String get extensionsDownloadPrioritySubtitle =>
       'Установка порядок сервисов скачивания';
 
+  @override
+  String get extensionsFallbackTitle => 'Fallback Extensions';
+
+  @override
+  String get extensionsFallbackSubtitle =>
+      'Choose which installed download extensions can be used as fallback';
+
   @override
   String get extensionsNoDownloadProvider =>
       'Нет расширений с провайдером загрузки';
@@ -1642,9 +1669,9 @@ class AppLocalizationsRu extends AppLocalizations {
       count,
       locale: localeName,
       other: 'треков',
+      one: 'трек',
       many: 'треков',
       few: 'трека',
-      one: 'трек',
     );
     return 'Удалить $count $_temp0 из этого альбома?\n\nЭто также удалит файлы из хранилища.';
   }
@@ -1666,9 +1693,9 @@ class AppLocalizationsRu extends AppLocalizations {
       count,
       locale: localeName,
       other: 'треков',
+      one: 'трек',
       many: 'треков',
       few: 'трека',
-      one: 'трек',
     );
     return 'Удалить $count $_temp0';
   }
@@ -1899,9 +1926,9 @@ class AppLocalizationsRu extends AppLocalizations {
       count,
       locale: localeName,
       other: 'треков',
+      one: 'трек',
       many: 'треков',
       few: 'трека',
-      one: 'трек',
     );
     return '$_temp0';
   }
@@ -2055,9 +2082,9 @@ class AppLocalizationsRu extends AppLocalizations {
       count,
       locale: localeName,
       other: '$count минут',
+      one: '1 минуту',
       many: '$count минут',
       few: '$count минуты',
-      one: '$count минуту',
     );
     return '$_temp0 назад';
   }
@@ -2068,9 +2095,9 @@ class AppLocalizationsRu extends AppLocalizations {
       count,
       locale: localeName,
       other: '$count часов',
+      one: '1 час',
       many: '$count часов',
       few: '$count часа',
-      one: '$count час',
     );
     return '$_temp0 назад';
   }
@@ -2136,7 +2163,7 @@ class AppLocalizationsRu extends AppLocalizations {
 
   @override
   String get tutorialExtensionsTip1 =>
-      'Просмотрите вкладку Магазина, чтобы найти полезные расширения';
+      'Browse the Repo tab to discover useful extensions';
 
   @override
   String get tutorialExtensionsTip2 =>
@@ -2420,7 +2447,8 @@ class AppLocalizationsRu extends AppLocalizations {
   String get trackConvertFormat => 'Переконвертировать формат';
 
   @override
-  String get trackConvertFormatSubtitle => 'Конвертировать в MP3 или Opus';
+  String get trackConvertFormatSubtitle =>
+      'Convert to MP3, Opus, ALAC, or FLAC';
 
   @override
   String get trackConvertTitle => 'Конвертировать аудио';
@@ -2551,9 +2579,9 @@ class AppLocalizationsRu extends AppLocalizations {
       count,
       locale: localeName,
       other: '$count треков',
+      one: '1 трек',
       many: '$count треков',
       few: '$count трека',
-      one: '$count трек',
     );
     return '$_temp0';
   }
@@ -2670,9 +2698,9 @@ class AppLocalizationsRu extends AppLocalizations {
       count,
       locale: localeName,
       other: 'треков',
+      one: 'трек',
       many: 'треков',
       few: 'трека',
-      one: 'трек',
     );
     return 'Отправить $count $_temp0';
   }
@@ -2687,9 +2715,9 @@ class AppLocalizationsRu extends AppLocalizations {
       count,
       locale: localeName,
       other: 'треков',
+      one: 'трек',
       many: 'треков',
       few: 'трека',
-      one: 'трек',
     );
     return 'Конвертировать $count $_temp0';
   }

lib/l10n/arb/app_en.arb

@@ -158,6 +158,14 @@
       }
     }
   },
+  "optionsDefaultSearchTab": "Default Search Tab",
+  "@optionsDefaultSearchTab": {
+    "description": "Title for the preferred default search tab setting"
+  },
+  "optionsDefaultSearchTabSubtitle": "Choose which tab opens first for new search results.",
+  "@optionsDefaultSearchTabSubtitle": {
+    "description": "Subtitle for the preferred default search tab setting"
+  },
   "optionsSwitchBack": "Tap Deezer or Spotify to switch back from extension",
   "@optionsSwitchBack": {
     "description": "Hint to switch back to built-in providers"
@@ -422,6 +430,10 @@
   "@aboutPCSource": {
     "description": "Link to PC GitHub repo"
   },
+  "aboutKeepAndroidOpen": "Keep Android Open",
+  "@aboutKeepAndroidOpen": {
+    "description": "Link to Keep Android Open campaign website"
+  },
   "aboutReportIssue": "Report an issue",
   "@aboutReportIssue": {
     "description": "Link to report bugs"
@@ -1203,6 +1215,18 @@
   "@providerPriorityInfo": {
     "description": "Info tip about fallback behavior"
   },
+  "providerPriorityFallbackExtensionsTitle": "Extension Fallback",
+  "@providerPriorityFallbackExtensionsTitle": {
+    "description": "Section title for choosing which download extensions can be used as fallback providers"
+  },
+  "providerPriorityFallbackExtensionsDescription": "Choose which installed download extensions can be used during automatic fallback. Built-in providers still follow the priority order above.",
+  "@providerPriorityFallbackExtensionsDescription": {
+    "description": "Section description for extension fallback selection"
+  },
+  "providerPriorityFallbackExtensionsHint": "Only enabled extensions with download-provider capability are listed here.",
+  "@providerPriorityFallbackExtensionsHint": {
+    "description": "Hint below the extension fallback selection list"
+  },
   "providerBuiltIn": "Built-in",
   "@providerBuiltIn": {
     "description": "Label for built-in providers (Tidal/Qobuz)"
@@ -1857,6 +1881,14 @@
   "@extensionsDownloadPrioritySubtitle": {
     "description": "Subtitle for download priority"
   },
+  "extensionsFallbackTitle": "Fallback Extensions",
+  "@extensionsFallbackTitle": {
+    "description": "Setting and page title for choosing which download extensions can be used during fallback"
+  },
+  "extensionsFallbackSubtitle": "Choose which installed download extensions can be used as fallback",
+  "@extensionsFallbackSubtitle": {
+    "description": "Subtitle for download fallback extensions menu"
+  },
   "extensionsNoDownloadProvider": "No extensions with download provider",
   "@extensionsNoDownloadProvider": {
     "description": "Empty state - no download providers"

lib/l10n/arb/app_es.arb

@@ -362,6 +362,10 @@
   "@aboutPCSource": {
     "description": "Link to PC GitHub repo"
   },
+  "aboutKeepAndroidOpen": "Keep Android Open",
+  "@aboutKeepAndroidOpen": {
+    "description": "Link to Keep Android Open campaign website"
+  },
   "aboutReportIssue": "Report an issue",
   "@aboutReportIssue": {
     "description": "Link to report bugs"

lib/l10n/arb/app_pt.arb

@@ -362,6 +362,10 @@
   "@aboutPCSource": {
     "description": "Link to PC GitHub repo"
   },
+  "aboutKeepAndroidOpen": "Keep Android Open",
+  "@aboutKeepAndroidOpen": {
+    "description": "Link to Keep Android Open campaign website"
+  },
   "aboutReportIssue": "Report an issue",
   "@aboutReportIssue": {
     "description": "Link to report bugs"

lib/l10n/arb/app_zh.arb

@@ -362,6 +362,10 @@
   "@aboutPCSource": {
     "description": "Link to PC GitHub repo"
   },
+  "aboutKeepAndroidOpen": "Keep Android Open",
+  "@aboutKeepAndroidOpen": {
+    "description": "Link to Keep Android Open campaign website"
+  },
   "aboutReportIssue": "Report an issue",
   "@aboutReportIssue": {
     "description": "Link to report bugs"

lib/l10n/supported_locales.dart

@@ -20,6 +20,7 @@ const List<Locale> filteredSupportedLocales = <Locale>[
   Locale('pt', 'PT'),
   Locale('ja'),
   Locale('tr'),
+  Locale('uk'),
 ];
 
 /// Set of locale codes for quick lookup.
@@ -31,4 +32,5 @@ const Set<String> filteredLocaleCodes = <String>{
   'pt_PT',
   'ja',
   'tr',
+  'uk',
 };

lib/models/settings.dart

@@ -33,7 +33,9 @@ class AppSettings {
   final bool askQualityBeforeDownload;
   final bool enableLogging;
   final bool useExtensionProviders;
+  final List<String>? downloadFallbackExtensionIds;
   final String? searchProvider;
+  final String defaultSearchTab;
   final String? homeFeedProvider;
   final bool separateSingles;
   final String singleFilenameFormat;
@@ -108,7 +110,9 @@ class AppSettings {
     this.askQualityBeforeDownload = true,
     this.enableLogging = false,
     this.useExtensionProviders = true,
+    this.downloadFallbackExtensionIds,
     this.searchProvider,
+    this.defaultSearchTab = 'all',
     this.homeFeedProvider,
     this.separateSingles = false,
     this.singleFilenameFormat = '{title} - {artist}',
@@ -170,8 +174,11 @@ class AppSettings {
     bool? askQualityBeforeDownload,
     bool? enableLogging,
     bool? useExtensionProviders,
+    List<String>? downloadFallbackExtensionIds,
+    bool clearDownloadFallbackExtensionIds = false,
     String? searchProvider,
     bool clearSearchProvider = false,
+    String? defaultSearchTab,
     String? homeFeedProvider,
     bool clearHomeFeedProvider = false,
     bool? separateSingles,
@@ -232,9 +239,13 @@ class AppSettings {
       enableLogging: enableLogging ?? this.enableLogging,
       useExtensionProviders:
           useExtensionProviders ?? this.useExtensionProviders,
+      downloadFallbackExtensionIds: clearDownloadFallbackExtensionIds
+          ? null
+          : (downloadFallbackExtensionIds ?? this.downloadFallbackExtensionIds),
       searchProvider: clearSearchProvider
           ? null
           : (searchProvider ?? this.searchProvider),
+      defaultSearchTab: defaultSearchTab ?? this.defaultSearchTab,
       homeFeedProvider: clearHomeFeedProvider
           ? null
           : (homeFeedProvider ?? this.homeFeedProvider),

lib/models/settings.g.dart

@@ -35,7 +35,12 @@ AppSettings _$AppSettingsFromJson(Map<String, dynamic> json) => AppSettings(
   askQualityBeforeDownload: json['askQualityBeforeDownload'] as bool? ?? true,
   enableLogging: json['enableLogging'] as bool? ?? false,
   useExtensionProviders: json['useExtensionProviders'] as bool? ?? true,
+  downloadFallbackExtensionIds:
+      (json['downloadFallbackExtensionIds'] as List<dynamic>?)
+          ?.map((e) => e as String)
+          .toList(),
   searchProvider: json['searchProvider'] as String?,
+  defaultSearchTab: json['defaultSearchTab'] as String? ?? 'all',
   homeFeedProvider: json['homeFeedProvider'] as String?,
   separateSingles: json['separateSingles'] as bool? ?? false,
   singleFilenameFormat:
@@ -105,7 +110,9 @@ Map<String, dynamic> _$AppSettingsToJson(
   'askQualityBeforeDownload': instance.askQualityBeforeDownload,
   'enableLogging': instance.enableLogging,
   'useExtensionProviders': instance.useExtensionProviders,
+  'downloadFallbackExtensionIds': instance.downloadFallbackExtensionIds,
   'searchProvider': instance.searchProvider,
+  'defaultSearchTab': instance.defaultSearchTab,
   'homeFeedProvider': instance.homeFeedProvider,
   'separateSingles': instance.separateSingles,
   'singleFilenameFormat': instance.singleFilenameFormat,

lib/models/track.dart

@@ -16,12 +16,14 @@ class Track {
   final int duration;
   final int? trackNumber;
   final int? discNumber;
+  final int? totalDiscs;
   final String? releaseDate;
   final String? deezerId;
   final ServiceAvailability? availability;
   final String? source;
   final String? albumType;
   final int? totalTracks;
+  final String? composer;
   final String? itemType;
 
   const Track({
@@ -37,12 +39,14 @@ class Track {
     required this.duration,
     this.trackNumber,
     this.discNumber,
+    this.totalDiscs,
     this.releaseDate,
     this.deezerId,
     this.availability,
     this.source,
     this.albumType,
     this.totalTracks,
+    this.composer,
     this.itemType,
   });
 

lib/models/track.g.dart

@@ -19,6 +19,7 @@ Track _$TrackFromJson(Map<String, dynamic> json) => Track(
   duration: (json['duration'] as num).toInt(),
   trackNumber: (json['trackNumber'] as num?)?.toInt(),
   discNumber: (json['discNumber'] as num?)?.toInt(),
+  totalDiscs: (json['totalDiscs'] as num?)?.toInt(),
   releaseDate: json['releaseDate'] as String?,
   deezerId: json['deezerId'] as String?,
   availability: json['availability'] == null
@@ -29,6 +30,7 @@ Track _$TrackFromJson(Map<String, dynamic> json) => Track(
   source: json['source'] as String?,
   albumType: json['albumType'] as String?,
   totalTracks: (json['totalTracks'] as num?)?.toInt(),
+  composer: json['composer'] as String?,
   itemType: json['itemType'] as String?,
 );
 
@@ -45,12 +47,14 @@ Map<String, dynamic> _$TrackToJson(Track instance) => <String, dynamic>{
   'duration': instance.duration,
   'trackNumber': instance.trackNumber,
   'discNumber': instance.discNumber,
+  'totalDiscs': instance.totalDiscs,
   'releaseDate': instance.releaseDate,
   'deezerId': instance.deezerId,
   'availability': instance.availability,
   'source': instance.source,
   'albumType': instance.albumType,
   'totalTracks': instance.totalTracks,
+  'composer': instance.composer,
   'itemType': instance.itemType,
 };
 

lib/providers/extension_provider.dart

@@ -20,7 +20,6 @@ class Extension {
   final String name;
   final String displayName;
   final String version;
-  final String author;
   final String description;
   final bool enabled;
   final String status;
@@ -45,7 +44,6 @@ class Extension {
     required this.name,
     required this.displayName,
     required this.version,
-    required this.author,
     required this.description,
     required this.enabled,
     required this.status,
@@ -73,7 +71,6 @@ class Extension {
       displayName:
           json['display_name'] as String? ?? json['name'] as String? ?? '',
       version: json['version'] as String? ?? '0.0.0',
-      author: json['author'] as String? ?? 'Unknown',
       description: json['description'] as String? ?? '',
       enabled: json['enabled'] as bool? ?? false,
       status: json['status'] as String? ?? 'loaded',
@@ -124,7 +121,6 @@ class Extension {
     String? name,
     String? displayName,
     String? version,
-    String? author,
     String? description,
     bool? enabled,
     String? status,
@@ -149,7 +145,6 @@ class Extension {
       name: name ?? this.name,
       displayName: displayName ?? this.displayName,
       version: version ?? this.version,
-      author: author ?? this.author,
       description: description ?? this.description,
       enabled: enabled ?? this.enabled,
       status: status ?? this.status,
@@ -178,6 +173,26 @@ class Extension {
   bool get hasPostProcessing => postProcessing?.enabled ?? false;
   bool get hasHomeFeed => capabilities['homeFeed'] == true;
   bool get hasBrowseCategories => capabilities['browseCategories'] == true;
+  String? get preferredDownloadOutputExtension {
+    final value = capabilities['downloadOutputExtension'];
+    if (value is! String) return null;
+    final trimmed = value.trim();
+    return trimmed.isEmpty ? null : trimmed;
+  }
+
+  List<String> get preservedNativeOutputExtensions {
+    final value = capabilities['preserveNativeOutputExtensions'];
+    if (value is! List) return const [];
+
+    final normalized = <String>[];
+    for (final item in value) {
+      if (item is! String) continue;
+      final trimmed = item.trim().toLowerCase();
+      if (trimmed.isEmpty) continue;
+      normalized.add(trimmed.startsWith('.') ? trimmed : '.$trimmed');
+    }
+    return normalized;
+  }
 }
 
 class SearchFilter {
@@ -481,8 +496,10 @@ class ExtensionState {
 }
 
 class ExtensionNotifier extends Notifier<ExtensionState> {
+  static const _builtInMetadataProviders = ['qobuz', 'tidal'];
   AppLifecycleListener? _appLifecycleListener;
   bool _cleanupInFlight = false;
+  Completer<void>? _initializationCompleter;
 
   @override
   ExtensionState build() {
@@ -520,6 +537,13 @@ class ExtensionNotifier extends Notifier<ExtensionState> {
 
   Future<void> initialize(String extensionsDir, String dataDir) async {
     if (state.isInitialized) return;
+    if (_initializationCompleter != null) {
+      await _initializationCompleter!.future;
+      return;
+    }
+
+    final completer = Completer<void>();
+    _initializationCompleter = completer;
 
     state = state.copyWith(isLoading: true, error: null);
 
@@ -531,6 +555,8 @@ class ExtensionNotifier extends Notifier<ExtensionState> {
         error: null,
       );
       _log.i('Extension system disabled on this platform');
+      completer.complete();
+      _initializationCompleter = null;
       return;
     }
 
@@ -544,6 +570,32 @@ class ExtensionNotifier extends Notifier<ExtensionState> {
     } catch (e) {
       _log.e('Failed to initialize extension system: $e');
       state = state.copyWith(isLoading: false, error: e.toString());
+    } finally {
+      if (!completer.isCompleted) {
+        completer.complete();
+      }
+      if (identical(_initializationCompleter, completer)) {
+        _initializationCompleter = null;
+      }
+    }
+  }
+
+  Future<void> waitForInitialization({
+    Duration timeout = const Duration(seconds: 30),
+  }) async {
+    if (state.isInitialized || !PlatformBridge.supportsExtensionSystem) {
+      return;
+    }
+
+    final future = _initializationCompleter?.future;
+    if (future == null) {
+      return;
+    }
+
+    try {
+      await future.timeout(timeout);
+    } on TimeoutException {
+      _log.w('Timed out waiting for extension initialization after $timeout');
     }
   }
 
@@ -566,6 +618,7 @@ class ExtensionNotifier extends Notifier<ExtensionState> {
       final list = await PlatformBridge.getInstalledExtensions();
       final extensions = list.map((e) => Extension.fromJson(e)).toList();
       state = state.copyWith(extensions: extensions);
+      await _reconcileDownloadProviderPriority();
       _log.d('Loaded ${extensions.length} extensions');
 
       for (final ext in extensions) {
@@ -661,6 +714,7 @@ class ExtensionNotifier extends Notifier<ExtensionState> {
       }).toList();
 
       state = state.copyWith(extensions: extensions);
+      await _reconcileDownloadProviderPriority();
 
       if (!enabled && ext != null) {
         final settings = ref.read(settingsProvider);
@@ -685,6 +739,23 @@ class ExtensionNotifier extends Notifier<ExtensionState> {
     }
   }
 
+  Future<void> _reconcileDownloadProviderPriority() async {
+    if (state.providerPriority.isEmpty) {
+      return;
+    }
+
+    final sanitized = _sanitizeDownloadProviderPriority(state.providerPriority);
+    if (jsonEncode(sanitized) == jsonEncode(state.providerPriority)) {
+      return;
+    }
+
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setString(_providerPriorityKey, jsonEncode(sanitized));
+    await PlatformBridge.setProviderPriority(sanitized);
+    state = state.copyWith(providerPriority: sanitized);
+    _log.d('Reconciled provider priority after extension update: $sanitized');
+  }
+
   Future<bool> ensureSpotifyWebExtensionReady({
     bool setAsSearchProvider = true,
   }) async {
@@ -812,6 +883,7 @@ class ExtensionNotifier extends Notifier<ExtensionState> {
 
   List<String> _sanitizeDownloadProviderPriority(List<String> input) {
     final allowed = getAllDownloadProviders().toSet();
+    final preferredOrder = getAllDownloadProviders();
     final result = <String>[];
 
     for (final provider in input) {
@@ -820,7 +892,7 @@ class ExtensionNotifier extends Notifier<ExtensionState> {
       }
     }
 
-    for (final provider in const ['tidal', 'qobuz', 'deezer']) {
+    for (final provider in preferredOrder) {
       if (!result.contains(provider)) {
         result.add(provider);
       }
@@ -847,10 +919,15 @@ class ExtensionNotifier extends Notifier<ExtensionState> {
         );
         await PlatformBridge.setMetadataProviderPriority(priority);
       } else {
-        priority = _sanitizeMetadataProviderPriority(
-          await PlatformBridge.getMetadataProviderPriority(),
-        );
+        final backendPriority =
+            await PlatformBridge.getMetadataProviderPriority();
+        priority = _sanitizeMetadataProviderPriority(backendPriority);
         _log.d('Using default metadata provider priority: $priority');
+        await prefs.setString(
+          _metadataProviderPriorityKey,
+          jsonEncode(priority),
+        );
+        await PlatformBridge.setMetadataProviderPriority(priority);
       }
 
       state = state.copyWith(metadataProviderPriority: priority);
@@ -896,7 +973,7 @@ class ExtensionNotifier extends Notifier<ExtensionState> {
   }
 
   List<String> getAllDownloadProviders() {
-    final providers = ['tidal', 'qobuz', 'deezer'];
+    final providers = ['tidal', 'qobuz'];
     for (final ext in state.extensions) {
       if (ext.enabled && ext.hasDownloadProvider) {
         providers.add(ext.id);
@@ -906,17 +983,26 @@ class ExtensionNotifier extends Notifier<ExtensionState> {
   }
 
   List<String> getAllMetadataProviders() {
-    final providers = ['deezer', 'qobuz', 'tidal'];
-    for (final ext in state.extensions) {
-      if (ext.enabled && ext.hasMetadataProvider) {
-        providers.add(ext.id);
-      }
-    }
-    return providers;
+    final metadataExtensions = state.extensions
+        .where((ext) => ext.enabled && ext.hasMetadataProvider)
+        .toList();
+    final primarySearchMetadataExtensions = metadataExtensions
+        .where((ext) => ext.searchBehavior?.primary == true)
+        .map((ext) => ext.id);
+    final otherMetadataExtensions = metadataExtensions
+        .where((ext) => ext.searchBehavior?.primary != true)
+        .map((ext) => ext.id);
+
+    return [
+      ...primarySearchMetadataExtensions,
+      ..._builtInMetadataProviders,
+      ...otherMetadataExtensions,
+    ];
   }
 
   List<String> _sanitizeMetadataProviderPriority(List<String> input) {
     final allowed = getAllMetadataProviders().toSet();
+    final preferredOrder = getAllMetadataProviders();
     final result = <String>[];
 
     for (final provider in input) {
@@ -925,7 +1011,18 @@ class ExtensionNotifier extends Notifier<ExtensionState> {
       }
     }
 
-    for (final provider in const ['deezer', 'qobuz', 'tidal']) {
+    final hasPreferredExtension = preferredOrder.any(
+      (provider) => !_builtInMetadataProviders.contains(provider),
+    );
+    final hasSavedExtension = result.any(
+      (provider) => !_builtInMetadataProviders.contains(provider),
+    );
+
+    if (!hasSavedExtension && hasPreferredExtension) {
+      return List<String>.from(preferredOrder);
+    }
+
+    for (final provider in preferredOrder) {
       if (!result.contains(provider)) {
         result.add(provider);
       }

lib/providers/settings_provider.dart

@@ -12,12 +12,13 @@ import 'package:spotiflac_android/utils/logger.dart';
 
 const _settingsKey = 'app_settings';
 const _migrationVersionKey = 'settings_migration_version';
-const _currentMigrationVersion = 9;
+const _currentMigrationVersion = 10;
 const _spotifyClientSecretKey = 'spotify_client_secret';
 final _log = AppLogger('SettingsProvider');
 
 class SettingsNotifier extends Notifier<AppSettings> {
   static final RegExp _isoRegionPattern = RegExp(r'^[A-Z]{2}$');
+  static const Set<String> _searchTabValues = {'all', 'track', 'artist', 'album'};
 
   final Future<SharedPreferences> _prefs = SharedPreferences.getInstance();
   final FlutterSecureStorage _secureStorage = const FlutterSecureStorage();
@@ -35,9 +36,23 @@ class SettingsNotifier extends Notifier<AppSettings> {
     final prefs = await _prefs;
     final json = prefs.getString(_settingsKey);
     if (json != null) {
-      state = AppSettings.fromJson(
+      final loaded = AppSettings.fromJson(
         Map<String, dynamic>.from(jsonDecode(json) as Map),
       );
+      final sanitizedDownloadFallbackExtensionIds =
+          _sanitizeDownloadFallbackExtensionIds(
+            loaded.downloadFallbackExtensionIds,
+          );
+      final sanitizedDefaultSearchTab = _normalizeDefaultSearchTab(
+        loaded.defaultSearchTab,
+      );
+      state = loaded.copyWith(
+        downloadFallbackExtensionIds: sanitizedDownloadFallbackExtensionIds,
+        clearDownloadFallbackExtensionIds:
+            loaded.downloadFallbackExtensionIds != null &&
+            sanitizedDownloadFallbackExtensionIds == null,
+        defaultSearchTab: sanitizedDefaultSearchTab,
+      );
 
       await _runMigrations(prefs);
       await _normalizeIosDownloadDirectoryIfNeeded();
@@ -50,6 +65,7 @@ class SettingsNotifier extends Notifier<AppSettings> {
 
     _syncLyricsSettingsToBackend();
     _syncNetworkCompatibilitySettingsToBackend();
+    _syncExtensionFallbackSettingsToBackend();
   }
 
   void _syncLyricsSettingsToBackend() {
@@ -83,6 +99,16 @@ class SettingsNotifier extends Notifier<AppSettings> {
     });
   }
 
+  void _syncExtensionFallbackSettingsToBackend() {
+    if (!PlatformBridge.supportsCoreBackend) return;
+
+    PlatformBridge.setDownloadFallbackExtensionIds(
+      state.downloadFallbackExtensionIds,
+    ).catchError((Object e) {
+      _log.w('Failed to sync extension fallback settings to backend: $e');
+    });
+  }
+
   Future<void> _runMigrations(SharedPreferences prefs) async {
     final lastMigration = prefs.getInt(_migrationVersionKey) ?? 0;
 
@@ -111,8 +137,9 @@ class SettingsNotifier extends Notifier<AppSettings> {
         );
       }
       state = state.copyWith(lastSeenVersion: AppInfo.version);
-      // Migration 7: YouTube is no longer a built-in service — reset to Tidal
-      if (state.defaultService == 'youtube') {
+      // Migration 7/10: retired built-in services reset back to Tidal
+      if (state.defaultService == 'youtube' ||
+          state.defaultService == 'deezer') {
         state = state.copyWith(defaultService: 'tidal');
       }
       await prefs.setInt(_migrationVersionKey, _currentMigrationVersion);
@@ -165,6 +192,12 @@ class SettingsNotifier extends Notifier<AppSettings> {
     return 'US';
   }
 
+  String _normalizeDefaultSearchTab(String value) {
+    final normalized = value.trim().toLowerCase();
+    if (_searchTabValues.contains(normalized)) return normalized;
+    return 'all';
+  }
+
   Future<void> _normalizeSongLinkRegionIfNeeded() async {
     final normalized = _normalizeSongLinkRegion(state.songLinkRegion);
     if (normalized == state.songLinkRegion) return;
@@ -172,6 +205,22 @@ class SettingsNotifier extends Notifier<AppSettings> {
     await _saveSettings();
   }
 
+  List<String>? _sanitizeDownloadFallbackExtensionIds(List<String>? ids) {
+    if (ids == null) {
+      return null;
+    }
+
+    final result = <String>[];
+    for (final id in ids) {
+      final normalized = id.trim();
+      if (normalized.isEmpty || result.contains(normalized)) {
+        continue;
+      }
+      result.add(normalized);
+    }
+    return result;
+  }
+
   Future<void> _cleanupRetiredSpotifySettings() async {
     final storedSecret = await _secureStorage.read(
       key: _spotifyClientSecretKey,
@@ -370,6 +419,11 @@ class SettingsNotifier extends Notifier<AppSettings> {
     _saveSettings();
   }
 
+  void setDefaultSearchTab(String tab) {
+    state = state.copyWith(defaultSearchTab: _normalizeDefaultSearchTab(tab));
+    _saveSettings();
+  }
+
   void setHomeFeedProvider(String? provider) {
     if (provider == null || provider.isEmpty) {
       state = state.copyWith(clearHomeFeedProvider: true);
@@ -390,6 +444,17 @@ class SettingsNotifier extends Notifier<AppSettings> {
     _saveSettings();
   }
 
+  void setDownloadFallbackExtensionIds(List<String>? extensionIds) {
+    final sanitized = _sanitizeDownloadFallbackExtensionIds(extensionIds);
+    state = state.copyWith(
+      downloadFallbackExtensionIds: sanitized,
+      clearDownloadFallbackExtensionIds:
+          extensionIds == null && state.downloadFallbackExtensionIds != null,
+    );
+    _saveSettings();
+    _syncExtensionFallbackSettingsToBackend();
+  }
+
   void setSeparateSingles(bool enabled) {
     state = state.copyWith(separateSingles: enabled);
     _saveSettings();