perf+security: polling guards, sensitive data redaction, SAF path sanitization

Go backend:
- Add sensitive data redaction in log buffer (tokens, keys, passwords)
- Validate extension auth URLs (HTTPS only, no private IPs, no embedded creds)
- Block embedded credentials in extension HTTP requests
- Tighten extension storage file permissions (0644 -> 0600)
- Sanitize extension ID in store download path
- Summarize auth URLs in logs to prevent token leakage

Android (Kotlin):
- Add sanitizeRelativeDir to prevent path traversal in SAF operations
- Apply sanitizeFilename to all user-provided file names in SAF

Flutter:
- Add sensitive data redaction in Dart logger (mirrors Go patterns)
- Mask device ID in log exports
- Add in-flight guard to progress polling (download queue + local library)
- Remove redundant _downloadedSpotifyIds Set, use _bySpotifyId map
- Remove redundant _isrcSet, use _byIsrc map
- Expand DownloadQueueLookup with byItemId and itemIds
- Lazy search index building in queue tab
- Bound embedded cover cache in queue tab (max 180)
- Coalesce embedded cover refresh callbacks via postFrameCallback
- Cache album track filtering in downloaded album screen
- Cache thumbnail sizes by extension ID in home tab
- Simplify recent access aggregation (single-pass)
- Remove unused _isTyping state in home tab
- Cap pre-warm track batch size to 80
- Skip setShowingRecentAccess if value unchanged
- Use downloadQueueLookupProvider for granular queue selectors
- Move grouped album filtering before content data computation

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

@@ -300,8 +300,18 @@ class MainActivity: FlutterFragmentActivity() {
         return name.replace(Regex("[\\\\/:*?\"<>|]"), "_").trim()
     }
 
+    private fun sanitizeRelativeDir(relativeDir: String): String {
+        if (relativeDir.isBlank()) return ""
+        return relativeDir
+            .split("/")
+            .map { sanitizeFilename(it) }
+            .filter { it.isNotBlank() && it != "." && it != ".." }
+            .joinToString("/")
+    }
+
     private fun ensureDocumentDir(treeUri: Uri, relativeDir: String): DocumentFile? {
-        if (relativeDir.isBlank()) {
+        val safeRelativeDir = sanitizeRelativeDir(relativeDir)
+        if (safeRelativeDir.isBlank()) {
             return DocumentFile.fromTreeUri(this, treeUri)
         }
 
@@ -310,7 +320,7 @@ class MainActivity: FlutterFragmentActivity() {
         synchronized(safDirLock) {
             var current = DocumentFile.fromTreeUri(this, treeUri) ?: return null
 
-            val parts = relativeDir.split("/").filter { it.isNotBlank() }
+            val parts = safeRelativeDir.split("/").filter { it.isNotBlank() }
             for (part in parts) {
                 val existing = current.findFile(part)
                 current = if (existing != null && existing.isDirectory) {
@@ -335,9 +345,10 @@ class MainActivity: FlutterFragmentActivity() {
 
     private fun findDocumentDir(treeUri: Uri, relativeDir: String): DocumentFile? {
         var current = DocumentFile.fromTreeUri(this, treeUri) ?: return null
-        if (relativeDir.isBlank()) return current
+        val safeRelativeDir = sanitizeRelativeDir(relativeDir)
+        if (safeRelativeDir.isBlank()) return current
 
-        val parts = relativeDir.split("/").filter { it.isNotBlank() }
+        val parts = safeRelativeDir.split("/").filter { it.isNotBlank() }
         for (part in parts) {
             val existing = current.findFile(part)
             if (existing == null || !existing.isDirectory) return null
@@ -377,14 +388,21 @@ class MainActivity: FlutterFragmentActivity() {
             obj.put("relative_dir", "")
             return obj.toString()
         }
+        val safeRelativeDir = sanitizeRelativeDir(relativeDir)
+        val safeFileName = sanitizeFilename(fileName)
+        if (safeFileName.isBlank()) {
+            obj.put("uri", "")
+            obj.put("relative_dir", "")
+            return obj.toString()
+        }
 
         val treeUri = Uri.parse(treeUriStr)
-        val targetDir = findDocumentDir(treeUri, relativeDir)
+        val targetDir = findDocumentDir(treeUri, safeRelativeDir)
         if (targetDir != null) {
-            val direct = targetDir.findFile(fileName)
+            val direct = targetDir.findFile(safeFileName)
             if (direct != null && direct.isFile) {
                 obj.put("uri", direct.uri.toString())
-                obj.put("relative_dir", relativeDir)
+                obj.put("relative_dir", safeRelativeDir)
                 return obj.toString()
             }
         }
@@ -410,7 +428,7 @@ class MainActivity: FlutterFragmentActivity() {
                     val childPath = if (path.isBlank()) childName else "$path/$childName"
                     queue.add(child to childPath)
                 } else if (child.isFile) {
-                    if (child.name == fileName) {
+                    if (child.name == safeFileName) {
                         obj.put("uri", child.uri.toString())
                         obj.put("relative_dir", path)
                         return obj.toString()
@@ -426,7 +444,7 @@ class MainActivity: FlutterFragmentActivity() {
 
     private fun buildSafFileName(req: JSONObject, outputExt: String): String {
         val provided = req.optString("saf_file_name", "")
-        if (provided.isNotBlank()) return provided
+        if (provided.isNotBlank()) return sanitizeFilename(provided)
 
         val trackName = req.optString("track_name", "track")
         val artistName = req.optString("artist_name", "")
@@ -617,7 +635,7 @@ class MainActivity: FlutterFragmentActivity() {
         }
 
         val treeUri = Uri.parse(treeUriStr)
-        val relativeDir = req.optString("saf_relative_dir", "")
+        val relativeDir = sanitizeRelativeDir(req.optString("saf_relative_dir", ""))
         val outputExt = normalizeExt(req.optString("saf_output_ext", ""))
         val mimeType = mimeTypeForExt(outputExt)
         val fileName = buildSafFileName(req, outputExt)
@@ -1474,11 +1492,12 @@ class MainActivity: FlutterFragmentActivity() {
                         "safCreateFromPath" -> {
                             val treeUriStr = call.argument<String>("tree_uri") ?: ""
                             val relativeDir = call.argument<String>("relative_dir") ?: ""
-                            val fileName = call.argument<String>("file_name") ?: ""
+                            val fileName = sanitizeFilename(call.argument<String>("file_name") ?: "")
                             val mimeType = call.argument<String>("mime_type") ?: "application/octet-stream"
                             val srcPath = call.argument<String>("src_path") ?: ""
                             val createdUri = withContext(Dispatchers.IO) {
                                 if (treeUriStr.isBlank()) return@withContext null
+                                if (fileName.isBlank()) return@withContext null
                                 val dir = ensureDocumentDir(Uri.parse(treeUriStr), relativeDir) ?: return@withContext null
                                 val existing = dir.findFile(fileName)
                                 val createdNew = existing == null

go_backend/exports.go

@@ -2906,14 +2906,26 @@ func GetStoreCategoriesJSON() (string, error) {
 	return string(jsonBytes), nil
 }
 
+func buildStoreExtensionDestPath(destDir, extensionID string) (string, error) {
+	if strings.TrimSpace(extensionID) == "" {
+		return "", fmt.Errorf("invalid extension id")
+	}
+
+	safeExtensionID := sanitizeFilename(extensionID)
+	return filepath.Join(destDir, safeExtensionID+".spotiflac-ext"), nil
+}
+
 func DownloadStoreExtensionJSON(extensionID, destDir string) (string, error) {
 	store := GetExtensionStore()
 	if store == nil {
 		return "", fmt.Errorf("extension store not initialized")
 	}
 
-	destPath := fmt.Sprintf("%s/%s.spotiflac-ext", destDir, extensionID)
+	destPath, err := buildStoreExtensionDestPath(destDir, extensionID)
-	err := store.DownloadExtension(extensionID, destPath)
+	if err != nil {
+		return "", err
+	}
+	err = store.DownloadExtension(extensionID, destPath)
 	if err != nil {
 		return "", err
 	}

go_backend/extension_runtime_auth.go

@@ -18,6 +18,43 @@ import (
 
 // ==================== Auth API (OAuth Support) ====================
 
+func validateExtensionAuthURL(urlStr string) error {
+	parsed, err := url.Parse(urlStr)
+	if err != nil {
+		return fmt.Errorf("invalid auth URL: %w", err)
+	}
+
+	if parsed.Scheme != "https" {
+		return fmt.Errorf("invalid auth URL: only https is allowed")
+	}
+
+	host := parsed.Hostname()
+	if host == "" {
+		return fmt.Errorf("invalid auth URL: hostname is required")
+	}
+
+	if parsed.User != nil {
+		return fmt.Errorf("invalid auth URL: embedded credentials are not allowed")
+	}
+
+	if isPrivateIP(host) {
+		return fmt.Errorf("invalid auth URL: private/local network is not allowed")
+	}
+
+	return nil
+}
+
+func summarizeURLForLog(urlStr string) string {
+	parsed, err := url.Parse(urlStr)
+	if err != nil {
+		return urlStr
+	}
+	if parsed.Host == "" {
+		return parsed.Scheme + "://"
+	}
+	return fmt.Sprintf("%s://%s%s", parsed.Scheme, parsed.Host, parsed.Path)
+}
+
 func (r *ExtensionRuntime) authOpenUrl(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -32,6 +69,13 @@ func (r *ExtensionRuntime) authOpenUrl(call goja.FunctionCall) goja.Value {
 		callbackURL = call.Arguments[1].String()
 	}
 
+	if err := validateExtensionAuthURL(authURL); err != nil {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   err.Error(),
+		})
+	}
+
 	pendingAuthRequestsMu.Lock()
 	pendingAuthRequests[r.extensionID] = &PendingAuthRequest{
 		ExtensionID: r.extensionID,
@@ -50,7 +94,7 @@ func (r *ExtensionRuntime) authOpenUrl(call goja.FunctionCall) goja.Value {
 	state.AuthCode = ""
 	extensionAuthStateMu.Unlock()
 
-	GoLog("[Extension:%s] Auth URL requested: %s\n", r.extensionID, authURL)
+	GoLog("[Extension:%s] Auth URL requested: %s\n", r.extensionID, summarizeURLForLog(authURL))
 
 	return r.vm.ToValue(map[string]interface{}{
 		"success": true,
@@ -273,6 +317,12 @@ func (r *ExtensionRuntime) authStartOAuthWithPKCE(call goja.FunctionCall) goja.V
 			"error":   "authUrl, clientId, and redirectUri are required",
 		})
 	}
+	if err := validateExtensionAuthURL(authURL); err != nil {
+		return r.vm.ToValue(map[string]interface{}{
+			"success": false,
+			"error":   err.Error(),
+		})
+	}
 
 	scope, _ := config["scope"].(string)
 	extraParams, _ := config["extraParams"].(map[string]interface{})
@@ -331,7 +381,7 @@ func (r *ExtensionRuntime) authStartOAuthWithPKCE(call goja.FunctionCall) goja.V
 	}
 	pendingAuthRequestsMu.Unlock()
 
-	GoLog("[Extension:%s] PKCE OAuth started: %s\n", r.extensionID, fullAuthURL)
+	GoLog("[Extension:%s] PKCE OAuth started: %s\n", r.extensionID, summarizeURLForLog(fullAuthURL))
 
 	return r.vm.ToValue(map[string]interface{}{
 		"success": true,
@@ -441,13 +491,17 @@ func (r *ExtensionRuntime) authExchangeCodeWithPKCE(call goja.FunctionCall) goja
 			"error":   err.Error(),
 		})
 	}
+	bodyPreview := sanitizeSensitiveLogText(string(body))
+	if len(bodyPreview) > 1000 {
+		bodyPreview = bodyPreview[:1000] + "...[truncated]"
+	}
 
 	var tokenResp map[string]interface{}
 	if err := json.Unmarshal(body, &tokenResp); err != nil {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
 			"error":   fmt.Sprintf("failed to parse token response: %v", err),
-			"body":    string(body),
+			"body":    bodyPreview,
 		})
 	}
 
@@ -468,7 +522,7 @@ func (r *ExtensionRuntime) authExchangeCodeWithPKCE(call goja.FunctionCall) goja
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
 			"error":   "no access_token in response",
-			"body":    string(body),
+			"body":    bodyPreview,
 		})
 	}
 

go_backend/extension_runtime_http.go

@@ -32,6 +32,9 @@ func (r *ExtensionRuntime) validateDomain(urlStr string) error {
 	if parsed.Scheme != "https" {
 		return fmt.Errorf("network access denied: only https is allowed")
 	}
+	if parsed.User != nil {
+		return fmt.Errorf("invalid URL: embedded credentials are not allowed")
+	}
 
 	domain := parsed.Hostname()
 	if domain == "" {

go_backend/extension_runtime_storage.go

@@ -46,7 +46,7 @@ func (r *ExtensionRuntime) saveStorage(storage map[string]interface{}) error {
 		return err
 	}
 
-	return os.WriteFile(storagePath, data, 0644)
+	return os.WriteFile(storagePath, data, 0600)
 }
 
 func (r *ExtensionRuntime) storageGet(call goja.FunctionCall) goja.Value {

go_backend/logbuffer.go

@@ -3,6 +3,7 @@ package gobackend
 import (
 	"encoding/json"
 	"fmt"
+	"regexp"
 	"strings"
 	"sync"
 	"time"
@@ -30,8 +31,22 @@ const (
 var (
 	globalLogBuffer *LogBuffer
 	logBufferOnce   sync.Once
+
+	authorizationBearerPattern = regexp.MustCompile(`(?i)\bAuthorization\b\s*[:=]\s*Bearer\s+[A-Za-z0-9._~+/\-]+=*`)
+	genericKeyValuePattern     = regexp.MustCompile(`(?i)\b(access[_\s-]?token|refresh[_\s-]?token|id[_\s-]?token|client[_\s-]?secret|authorization|password|api[_\s-]?key)\b(\s*[:=]\s*)([^\s,;]+)`)
+	queryTokenPattern          = regexp.MustCompile(`(?i)([?&](?:access_token|refresh_token|id_token|token|client_secret|api_key|apikey|password)=)[^&\s]+`)
+	bearerTokenPattern         = regexp.MustCompile(`(?i)\bBearer\s+[A-Za-z0-9._~+/\-]+=*`)
 )
 
+func sanitizeSensitiveLogText(message string) string {
+	redacted := message
+	redacted = authorizationBearerPattern.ReplaceAllString(redacted, "Authorization: Bearer [REDACTED]")
+	redacted = genericKeyValuePattern.ReplaceAllString(redacted, `${1}${2}[REDACTED]`)
+	redacted = queryTokenPattern.ReplaceAllString(redacted, `${1}[REDACTED]`)
+	redacted = bearerTokenPattern.ReplaceAllString(redacted, "Bearer [REDACTED]")
+	return redacted
+}
+
 func GetLogBuffer() *LogBuffer {
 	logBufferOnce.Do(func() {
 		globalLogBuffer = &LogBuffer{
@@ -71,6 +86,7 @@ func (lb *LogBuffer) Add(level, tag, message string) {
 		return
 	}
 
+	message = sanitizeSensitiveLogText(message)
 	message = truncateLogMessage(message)
 
 	entry := LogEntry{

go_backend/security_hardening_test.go

@@ -0,0 +1,80 @@
+package gobackend
+
+import (
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestSanitizeSensitiveLogText(t *testing.T) {
+	input := "access_token=abc123 Authorization:Bearer xyz456 https://api.example.com/cb?refresh_token=zzz"
+	redacted := sanitizeSensitiveLogText(input)
+
+	if strings.Contains(redacted, "abc123") || strings.Contains(redacted, "xyz456") || strings.Contains(redacted, "zzz") {
+		t.Fatalf("expected sensitive values to be redacted, got: %s", redacted)
+	}
+	if !strings.Contains(redacted, "[REDACTED]") {
+		t.Fatalf("expected redaction marker in output, got: %s", redacted)
+	}
+}
+
+func TestValidateExtensionAuthURL(t *testing.T) {
+	if err := validateExtensionAuthURL("https://accounts.example.com/oauth/authorize"); err != nil {
+		t.Fatalf("expected valid auth URL, got error: %v", err)
+	}
+
+	blocked := []string{
+		"http://accounts.example.com/oauth/authorize",
+		"https://user:pass@accounts.example.com/oauth/authorize",
+		"https://localhost/oauth/authorize",
+	}
+
+	for _, rawURL := range blocked {
+		if err := validateExtensionAuthURL(rawURL); err == nil {
+			t.Fatalf("expected URL to be blocked: %s", rawURL)
+		}
+	}
+}
+
+func TestValidateDomainRejectsEmbeddedCredentials(t *testing.T) {
+	ext := &LoadedExtension{
+		ID: "test-ext",
+		Manifest: &ExtensionManifest{
+			Name: "test-ext",
+			Permissions: ExtensionPermissions{
+				Network: []string{"api.example.com"},
+			},
+		},
+		DataDir: t.TempDir(),
+	}
+
+	runtime := NewExtensionRuntime(ext)
+	if err := runtime.validateDomain("https://user:pass@api.example.com/resource"); err == nil {
+		t.Fatal("expected embedded URL credentials to be rejected")
+	}
+}
+
+func TestBuildStoreExtensionDestPath(t *testing.T) {
+	baseDir := t.TempDir()
+
+	destPath, err := buildStoreExtensionDestPath(baseDir, "../evil/name")
+	if err != nil {
+		t.Fatalf("expected sanitized path to be generated, got error: %v", err)
+	}
+
+	if !isPathWithinBase(baseDir, destPath) {
+		t.Fatalf("expected destination path to remain under base dir: %s", destPath)
+	}
+
+	baseName := filepath.Base(destPath)
+	if strings.Contains(baseName, "/") || strings.Contains(baseName, `\`) {
+		t.Fatalf("expected filename to be sanitized, got: %s", baseName)
+	}
+	if !strings.HasSuffix(baseName, ".spotiflac-ext") {
+		t.Fatalf("expected .spotiflac-ext suffix, got: %s", baseName)
+	}
+
+	if _, err := buildStoreExtensionDestPath(baseDir, "   "); err == nil {
+		t.Fatal("expected empty extension id to be rejected")
+	}
+}

lib/providers/download_queue_provider.dart

@@ -208,16 +208,11 @@ class DownloadHistoryItem {
 
 class DownloadHistoryState {
   final List<DownloadHistoryItem> items;
-  final Set<String> _downloadedSpotifyIds;
   final Map<String, DownloadHistoryItem> _bySpotifyId;
   final Map<String, DownloadHistoryItem> _byIsrc;
 
   DownloadHistoryState({this.items = const []})
-    : _downloadedSpotifyIds = items
+    : _bySpotifyId = Map.fromEntries(
-          .where((item) => item.spotifyId != null && item.spotifyId!.isNotEmpty)
-          .map((item) => item.spotifyId!)
-          .toSet(),
-      _bySpotifyId = Map.fromEntries(
         items
             .where(
               (item) => item.spotifyId != null && item.spotifyId!.isNotEmpty,
@@ -230,8 +225,7 @@ class DownloadHistoryState {
             .map((item) => MapEntry(item.isrc!, item)),
       );
 
-  bool isDownloaded(String spotifyId) =>
+  bool isDownloaded(String spotifyId) => _bySpotifyId.containsKey(spotifyId);
-      _downloadedSpotifyIds.contains(spotifyId);
 
   DownloadHistoryItem? getBySpotifyId(String spotifyId) =>
       _bySpotifyId[spotifyId];
@@ -682,6 +676,7 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
   bool _isLoaded = false;
   final Set<String> _ensuredDirs = {};
   int _progressPollingErrorCount = 0;
+  bool _isProgressPollingInFlight = false;
   String? _lastServiceTrackName;
   String? _lastServiceArtistName;
   int _lastServicePercent = -1;
@@ -832,6 +827,8 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
   void _startMultiProgressPolling() {
     _progressTimer?.cancel();
     _progressTimer = Timer.periodic(_progressPollingInterval, (timer) async {
+      if (_isProgressPollingInFlight) return;
+      _isProgressPollingInFlight = true;
       try {
         final allProgress = await PlatformBridge.getAllDownloadProgress();
         final items = allProgress['items'] as Map<String, dynamic>? ?? {};
@@ -915,16 +912,18 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
               bytesReceived: normalizedBytes,
             );
 
-            final mbReceived = bytesReceived / (1024 * 1024);
+            if (LogBuffer.loggingEnabled) {
-            final mbTotal = bytesTotal / (1024 * 1024);
+              final mbReceived = bytesReceived / (1024 * 1024);
-            if (bytesTotal > 0) {
+              final mbTotal = bytesTotal / (1024 * 1024);
-              _log.d(
+              if (bytesTotal > 0) {
-                'Progress [$itemId]: ${(percentage * 100).toStringAsFixed(1)}% (${mbReceived.toStringAsFixed(2)}/${mbTotal.toStringAsFixed(2)} MB) @ ${speedMBps.toStringAsFixed(2)} MB/s',
+                _log.d(
-              );
+                  'Progress [$itemId]: ${(percentage * 100).toStringAsFixed(1)}% (${mbReceived.toStringAsFixed(2)}/${mbTotal.toStringAsFixed(2)} MB) @ ${speedMBps.toStringAsFixed(2)} MB/s',
-            } else {
+                );
-              _log.d(
+              } else {
-                'Progress [$itemId]: ${(percentage * 100).toStringAsFixed(1)}% (DASH segments/unknown size) @ ${speedMBps.toStringAsFixed(2)} MB/s',
+                _log.d(
-              );
+                  'Progress [$itemId]: ${(percentage * 100).toStringAsFixed(1)}% (DASH segments/unknown size) @ ${speedMBps.toStringAsFixed(2)} MB/s',
+                );
+              }
             }
           }
         }
@@ -1039,6 +1038,8 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
         if (_progressPollingErrorCount <= 3) {
           _log.w('Progress polling failed: $e');
         }
+      } finally {
+        _isProgressPollingInFlight = false;
       }
     });
   }
@@ -1088,6 +1089,7 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
     _progressTimer?.cancel();
     _progressTimer = null;
     _progressPollingErrorCount = 0;
+    _isProgressPollingInFlight = false;
     _lastServiceTrackName = null;
     _lastServiceArtistName = null;
     _lastServicePercent = -1;
@@ -4011,15 +4013,29 @@ final downloadQueueProvider =
 
 class DownloadQueueLookup {
   final Map<String, DownloadItem> byTrackId;
+  final Map<String, DownloadItem> byItemId;
+  final List<String> itemIds;
 
-  DownloadQueueLookup._(this.byTrackId);
+  DownloadQueueLookup._({
+    required this.byTrackId,
+    required this.byItemId,
+    required this.itemIds,
+  });
 
   factory DownloadQueueLookup.fromItems(List<DownloadItem> items) {
-    final map = <String, DownloadItem>{};
+    final byTrackId = <String, DownloadItem>{};
+    final byItemId = <String, DownloadItem>{};
+    final itemIds = <String>[];
     for (final item in items) {
-      map.putIfAbsent(item.track.id, () => item);
+      byTrackId.putIfAbsent(item.track.id, () => item);
+      byItemId[item.id] = item;
+      itemIds.add(item.id);
     }
-    return DownloadQueueLookup._(map);
+    return DownloadQueueLookup._(
+      byTrackId: byTrackId,
+      byItemId: byItemId,
+      itemIds: itemIds,
+    );
   }
 }
 

lib/providers/local_library_provider.dart

@@ -24,7 +24,6 @@ class LocalLibraryState {
   final bool scanWasCancelled;
   final DateTime? lastScannedAt;
   final int excludedDownloadedCount;
-  final Set<String> _isrcSet;
   final Set<String> _trackKeySet;
   final Map<String, LocalLibraryItem> _byIsrc;
 
@@ -39,16 +38,9 @@ class LocalLibraryState {
     this.scanWasCancelled = false,
     this.lastScannedAt,
     this.excludedDownloadedCount = 0,
-    Set<String>? isrcSet,
     Set<String>? trackKeySet,
     Map<String, LocalLibraryItem>? byIsrc,
-  }) : _isrcSet =
+  }) : _trackKeySet = trackKeySet ?? items.map((item) => item.matchKey).toSet(),
-           isrcSet ??
-           items
-               .where((item) => item.isrc != null && item.isrc!.isNotEmpty)
-               .map((item) => item.isrc!)
-               .toSet(),
-       _trackKeySet = trackKeySet ?? items.map((item) => item.matchKey).toSet(),
        _byIsrc =
            byIsrc ??
            Map.fromEntries(
@@ -57,7 +49,7 @@ class LocalLibraryState {
                  .map((item) => MapEntry(item.isrc!, item)),
            );
 
-  bool hasIsrc(String isrc) => _isrcSet.contains(isrc);
+  bool hasIsrc(String isrc) => _byIsrc.containsKey(isrc);
 
   bool hasTrack(String trackName, String artistName) {
     final key = '${trackName.toLowerCase()}|${artistName.toLowerCase()}';
@@ -108,7 +100,6 @@ class LocalLibraryState {
       lastScannedAt: lastScannedAt ?? this.lastScannedAt,
       excludedDownloadedCount:
           excludedDownloadedCount ?? this.excludedDownloadedCount,
-      isrcSet: keepDerivedIndex ? _isrcSet : null,
       trackKeySet: keepDerivedIndex ? _trackKeySet : null,
       byIsrc: keepDerivedIndex ? _byIsrc : null,
     );
@@ -123,6 +114,7 @@ class LocalLibraryNotifier extends Notifier<LocalLibraryState> {
   bool _isLoaded = false;
   bool _scanCancelRequested = false;
   int _progressPollingErrorCount = 0;
+  bool _isProgressPollingInFlight = false;
 
   @override
   LocalLibraryState build() {
@@ -408,6 +400,8 @@ class LocalLibraryNotifier extends Notifier<LocalLibraryState> {
   void _startProgressPolling() {
     _progressTimer?.cancel();
     _progressTimer = Timer.periodic(_progressPollingInterval, (_) async {
+      if (_isProgressPollingInFlight) return;
+      _isProgressPollingInFlight = true;
       try {
         final progress = await PlatformBridge.getLibraryScanProgress();
         final nextProgress =
@@ -447,6 +441,8 @@ class LocalLibraryNotifier extends Notifier<LocalLibraryState> {
         if (_progressPollingErrorCount <= 3) {
           _log.w('Library scan progress polling failed: $e');
         }
+      } finally {
+        _isProgressPollingInFlight = false;
       }
     });
   }
@@ -455,6 +451,7 @@ class LocalLibraryNotifier extends Notifier<LocalLibraryState> {
     _progressTimer?.cancel();
     _progressTimer = null;
     _progressPollingErrorCount = 0;
+    _isProgressPollingInFlight = false;
   }
 
   Future<void> cancelScan() async {

lib/providers/track_provider.dart

@@ -26,8 +26,10 @@ class TrackState {
   final List<SearchPlaylist>? searchPlaylists; // For search results (playlists)
   final bool hasSearchText; // For back button handling
   final bool isShowingRecentAccess; // For recent access mode
-  final String? searchExtensionId; // Extension ID used for current search results
+  final String?
-  final String? selectedSearchFilter; // Currently selected search filter (e.g., "track", "album", "artist", "playlist")
+  searchExtensionId; // Extension ID used for current search results
+  final String?
+  selectedSearchFilter; // Currently selected search filter (e.g., "track", "album", "artist", "playlist")
 
   const TrackState({
     this.tracks = const [],
@@ -52,7 +54,12 @@ class TrackState {
     this.selectedSearchFilter,
   });
 
-  bool get hasContent => tracks.isNotEmpty || artistAlbums != null || (searchArtists != null && searchArtists!.isNotEmpty) || (searchAlbums != null && searchAlbums!.isNotEmpty) || (searchPlaylists != null && searchPlaylists!.isNotEmpty);
+  bool get hasContent =>
+      tracks.isNotEmpty ||
+      artistAlbums != null ||
+      (searchArtists != null && searchArtists!.isNotEmpty) ||
+      (searchAlbums != null && searchAlbums!.isNotEmpty) ||
+      (searchPlaylists != null && searchPlaylists!.isNotEmpty);
 
   TrackState copyWith({
     List<Track>? tracks,
@@ -95,9 +102,12 @@ class TrackState {
       searchAlbums: searchAlbums ?? this.searchAlbums,
       searchPlaylists: searchPlaylists ?? this.searchPlaylists,
       hasSearchText: hasSearchText ?? this.hasSearchText,
-      isShowingRecentAccess: isShowingRecentAccess ?? this.isShowingRecentAccess,
+      isShowingRecentAccess:
+          isShowingRecentAccess ?? this.isShowingRecentAccess,
       searchExtensionId: searchExtensionId,
-      selectedSearchFilter: clearSelectedSearchFilter ? null : (selectedSearchFilter ?? this.selectedSearchFilter),
+      selectedSearchFilter: clearSelectedSearchFilter
+          ? null
+          : (selectedSearchFilter ?? this.selectedSearchFilter),
     );
   }
 }
@@ -178,6 +188,7 @@ class SearchPlaylist {
 
 class TrackNotifier extends Notifier<TrackState> {
   int _currentRequestId = 0;
+  static const int _maxPreWarmTracksPerRequest = 80;
 
   @override
   TrackState build() {
@@ -197,39 +208,42 @@ class TrackNotifier extends Notifier<TrackState> {
       final extensionHandler = await PlatformBridge.findURLHandler(url);
       if (extensionHandler != null) {
         _log.i('Found extension URL handler: $extensionHandler for URL: $url');
-        
+
         // Retry logic for extension URL handlers (up to 3 attempts)
         Map<String, dynamic>? result;
         for (int attempt = 1; attempt <= 3; attempt++) {
           result = await PlatformBridge.handleURLWithExtension(url);
           if (!_isRequestValid(requestId)) return;
-          
+
           // Check if we got valid data
-          if (result != null && result['type'] == 'track' && result['track'] != null) {
+          if (result != null &&
+              result['type'] == 'track' &&
+              result['track'] != null) {
             final trackData = result['track'] as Map<String, dynamic>;
             final name = trackData['name']?.toString() ?? '';
             if (name.isNotEmpty) {
               break;
             }
-          } else if (result != null && (result['type'] == 'album' || result['type'] == 'playlist')) {
+          } else if (result != null &&
+              (result['type'] == 'album' || result['type'] == 'playlist')) {
             break;
           } else if (result != null && result['type'] == 'artist') {
             break;
           }
-          
+
           if (attempt < 3) {
             await Future.delayed(const Duration(milliseconds: 500));
           }
         }
-        
+
         if (result != null) {
           final type = result['type'] as String?;
           final extensionId = result['extension_id'] as String?;
-          
+
           if (type == 'track' && result['track'] != null) {
             final trackData = result['track'] as Map<String, dynamic>;
             final track = _parseSearchTrack(trackData, source: extensionId);
-            
+
             if (track.name.isEmpty) {
               state = TrackState(
                 isLoading: false,
@@ -237,7 +251,7 @@ class TrackNotifier extends Notifier<TrackState> {
               );
               return;
             }
-            
+
             state = TrackState(
               tracks: [track],
               isLoading: false,
@@ -245,15 +259,27 @@ class TrackNotifier extends Notifier<TrackState> {
               searchExtensionId: extensionId,
             );
             return;
-          } else if ((type == 'album' || type == 'playlist') && result['tracks'] != null) {
+          } else if ((type == 'album' || type == 'playlist') &&
+              result['tracks'] != null) {
             final trackList = result['tracks'] as List<dynamic>;
-            final tracks = trackList.map((t) => _parseSearchTrack(t as Map<String, dynamic>, source: extensionId)).toList();
+            final tracks = trackList
+                .map(
+                  (t) => _parseSearchTrack(
+                    t as Map<String, dynamic>,
+                    source: extensionId,
+                  ),
+                )
+                .toList();
             state = TrackState(
               tracks: tracks,
               isLoading: false,
               albumId: result['album']?['id'] as String?,
-              albumName: result['name'] as String? ?? result['album']?['name'] as String?,
+              albumName:
-              playlistName: type == 'playlist' ? result['name'] as String? : null,
+                  result['name'] as String? ??
+                  result['album']?['name'] as String?,
+              playlistName: type == 'playlist'
+                  ? result['name'] as String?
+                  : null,
               coverUrl: result['cover_url'] as String?,
               searchExtensionId: extensionId,
             );
@@ -261,17 +287,29 @@ class TrackNotifier extends Notifier<TrackState> {
           } else if (type == 'artist' && result['artist'] != null) {
             final artistData = result['artist'] as Map<String, dynamic>;
             final albumsList = artistData['albums'] as List<dynamic>? ?? [];
-            final albums = albumsList.map((a) => _parseArtistAlbum(a as Map<String, dynamic>)).toList();
+            final albums = albumsList
-            
+                .map((a) => _parseArtistAlbum(a as Map<String, dynamic>))
-            final topTracksList = artistData['top_tracks'] as List<dynamic>? ?? [];
+                .toList();
-            final topTracks = topTracksList.map((t) => _parseSearchTrack(t as Map<String, dynamic>, source: extensionId)).toList();
+
-            
+            final topTracksList =
+                artistData['top_tracks'] as List<dynamic>? ?? [];
+            final topTracks = topTracksList
+                .map(
+                  (t) => _parseSearchTrack(
+                    t as Map<String, dynamic>,
+                    source: extensionId,
+                  ),
+                )
+                .toList();
+
             state = TrackState(
               tracks: [],
               isLoading: false,
               artistId: artistData['id'] as String?,
               artistName: artistData['name'] as String?,
-              coverUrl: artistData['image_url'] as String? ?? artistData['images'] as String?,
+              coverUrl:
+                  artistData['image_url'] as String? ??
+                  artistData['images'] as String?,
               headerImageUrl: artistData['header_image'] as String?,
               monthlyListeners: artistData['listeners'] as int?,
               artistAlbums: albums,
@@ -282,19 +320,19 @@ class TrackNotifier extends Notifier<TrackState> {
           }
         }
       }
-      
+
       // Step 2: Try Deezer URL parsing
       if (url.contains('deezer.com') || url.contains('deezer.page.link')) {
         _log.i('Detected Deezer URL, parsing...');
         final parsed = await PlatformBridge.parseDeezerUrl(url);
         if (!_isRequestValid(requestId)) return;
-        
+
         final type = parsed['type'] as String;
         final id = parsed['id'] as String;
-        
+
         final metadata = await PlatformBridge.getDeezerMetadata(type, id);
         if (!_isRequestValid(requestId)) return;
-        
+
         if (type == 'track') {
           final trackData = metadata['track'] as Map<String, dynamic>;
           final track = _parseTrack(trackData);
@@ -306,7 +344,9 @@ class TrackNotifier extends Notifier<TrackState> {
         } else if (type == 'album') {
           final albumInfo = metadata['album_info'] as Map<String, dynamic>;
           final trackList = metadata['track_list'] as List<dynamic>;
-          final tracks = trackList.map((t) => _parseTrack(t as Map<String, dynamic>)).toList();
+          final tracks = trackList
+              .map((t) => _parseTrack(t as Map<String, dynamic>))
+              .toList();
           state = TrackState(
             tracks: tracks,
             isLoading: false,
@@ -316,9 +356,12 @@ class TrackNotifier extends Notifier<TrackState> {
           );
           _preWarmCacheForTracks(tracks);
         } else if (type == 'playlist') {
-          final playlistInfo = metadata['playlist_info'] as Map<String, dynamic>;
+          final playlistInfo =
+              metadata['playlist_info'] as Map<String, dynamic>;
           final trackList = metadata['track_list'] as List<dynamic>;
-          final tracks = trackList.map((t) => _parseTrack(t as Map<String, dynamic>)).toList();
+          final tracks = trackList
+              .map((t) => _parseTrack(t as Map<String, dynamic>))
+              .toList();
           state = TrackState(
             tracks: tracks,
             isLoading: false,
@@ -329,7 +372,9 @@ class TrackNotifier extends Notifier<TrackState> {
         } else if (type == 'artist') {
           final artistInfo = metadata['artist_info'] as Map<String, dynamic>;
           final albumsList = metadata['albums'] as List<dynamic>;
-          final albums = albumsList.map((a) => _parseArtistAlbum(a as Map<String, dynamic>)).toList();
+          final albums = albumsList
+              .map((a) => _parseArtistAlbum(a as Map<String, dynamic>))
+              .toList();
           state = TrackState(
             tracks: [],
             isLoading: false,
@@ -341,33 +386,38 @@ class TrackNotifier extends Notifier<TrackState> {
         }
         return;
       }
-      
+
       // Step 3: Try Tidal URL parsing
       if (url.contains('tidal.com')) {
         _log.i('Detected Tidal URL, parsing...');
         final parsed = await PlatformBridge.parseTidalUrl(url);
         if (!_isRequestValid(requestId)) return;
-        
+
         final type = parsed['type'] as String;
         final id = parsed['id'] as String;
-        
+
         _log.i('Tidal URL parsed: type=$type, id=$id');
-        
+
         // For track URLs, convert to Spotify/Deezer and fetch metadata from there
         if (type == 'track') {
           try {
             _log.i('Converting Tidal track to Spotify/Deezer via SongLink...');
-            final conversion = await PlatformBridge.convertTidalToSpotifyDeezer(url);
+            final conversion = await PlatformBridge.convertTidalToSpotifyDeezer(
+              url,
+            );
             if (!_isRequestValid(requestId)) return;
-            
+
             final spotifyUrl = conversion['spotify_url'] as String?;
             final deezerUrl = conversion['deezer_url'] as String?;
-            
+
             if (spotifyUrl != null && spotifyUrl.isNotEmpty) {
               _log.i('Found Spotify URL: $spotifyUrl, fetching metadata...');
-              final metadata = await PlatformBridge.getSpotifyMetadataWithFallback(spotifyUrl);
+              final metadata =
+                  await PlatformBridge.getSpotifyMetadataWithFallback(
+                    spotifyUrl,
+                  );
               if (!_isRequestValid(requestId)) return;
-              
+
               final trackData = metadata['track'] as Map<String, dynamic>;
               final track = _parseTrack(trackData);
               state = TrackState(
@@ -378,10 +428,15 @@ class TrackNotifier extends Notifier<TrackState> {
               return;
             } else if (deezerUrl != null && deezerUrl.isNotEmpty) {
               _log.i('Found Deezer URL: $deezerUrl, fetching metadata...');
-              final deezerParsed = await PlatformBridge.parseDeezerUrl(deezerUrl);
+              final deezerParsed = await PlatformBridge.parseDeezerUrl(
-              final metadata = await PlatformBridge.getDeezerMetadata('track', deezerParsed['id'] as String);
+                deezerUrl,
+              );
+              final metadata = await PlatformBridge.getDeezerMetadata(
+                'track',
+                deezerParsed['id'] as String,
+              );
               if (!_isRequestValid(requestId)) return;
-              
+
               final trackData = metadata['track'] as Map<String, dynamic>;
               final track = _parseTrack(trackData);
               state = TrackState(
@@ -395,30 +450,31 @@ class TrackNotifier extends Notifier<TrackState> {
             _log.w('Failed to convert Tidal URL via SongLink: $e');
           }
         }
-        
+
         // For album/artist/playlist, not yet supported
         state = TrackState(
           isLoading: false,
-          error: 'Tidal $type links are not fully supported yet. Only track links work via SongLink conversion.',
+          error:
+              'Tidal $type links are not fully supported yet. Only track links work via SongLink conversion.',
           hasSearchText: state.hasSearchText,
         );
         return;
       }
-      
+
       // Step 4: Fall back to Spotify parsing
       final parsed = await PlatformBridge.parseSpotifyUrl(url);
       if (!_isRequestValid(requestId)) return;
-      
+
       final type = parsed['type'] as String;
 
       Map<String, dynamic> metadata;
-      
+
       try {
         metadata = await PlatformBridge.getSpotifyMetadataWithFallback(url);
       } catch (e) {
         rethrow;
       }
-      
+
       if (!_isRequestValid(requestId)) return;
 
       if (type == 'track') {
@@ -432,7 +488,9 @@ class TrackNotifier extends Notifier<TrackState> {
       } else if (type == 'album') {
         final albumInfo = metadata['album_info'] as Map<String, dynamic>;
         final trackList = metadata['track_list'] as List<dynamic>;
-        final tracks = trackList.map((t) => _parseTrack(t as Map<String, dynamic>)).toList();
+        final tracks = trackList
+            .map((t) => _parseTrack(t as Map<String, dynamic>))
+            .toList();
         state = TrackState(
           tracks: tracks,
           isLoading: false,
@@ -444,7 +502,9 @@ class TrackNotifier extends Notifier<TrackState> {
       } else if (type == 'playlist') {
         final playlistInfo = metadata['playlist_info'] as Map<String, dynamic>;
         final trackList = metadata['track_list'] as List<dynamic>;
-        final tracks = trackList.map((t) => _parseTrack(t as Map<String, dynamic>)).toList();
+        final tracks = trackList
+            .map((t) => _parseTrack(t as Map<String, dynamic>))
+            .toList();
         final owner = playlistInfo['owner'] as Map<String, dynamic>?;
         state = TrackState(
           tracks: tracks,
@@ -456,7 +516,9 @@ class TrackNotifier extends Notifier<TrackState> {
       } else if (type == 'artist') {
         final artistInfo = metadata['artist_info'] as Map<String, dynamic>;
         final albumsList = metadata['albums'] as List<dynamic>;
-        final albums = albumsList.map((a) => _parseArtistAlbum(a as Map<String, dynamic>)).toList();
+        final albums = albumsList
+            .map((a) => _parseArtistAlbum(a as Map<String, dynamic>))
+            .toList();
         state = TrackState(
           tracks: [],
           isLoading: false,
@@ -468,17 +530,29 @@ class TrackNotifier extends Notifier<TrackState> {
       }
     } catch (e) {
       if (!_isRequestValid(requestId)) return;
-      state = TrackState(isLoading: false, error: e.toString(), hasSearchText: state.hasSearchText);
+      state = TrackState(
+        isLoading: false,
+        error: e.toString(),
+        hasSearchText: state.hasSearchText,
+      );
     }
   }
 
-  Future<void> search(String query, {String? metadataSource, String? filterOverride}) async {
+  Future<void> search(
+    String query, {
+    String? metadataSource,
+    String? filterOverride,
+  }) async {
     final requestId = ++_currentRequestId;
-    
+
     // Preserve selected filter during loading
     final currentFilter = filterOverride ?? state.selectedSearchFilter;
 
-    state = TrackState(isLoading: true, hasSearchText: state.hasSearchText, selectedSearchFilter: currentFilter);
+    state = TrackState(
+      isLoading: true,
+      hasSearchText: state.hasSearchText,
+      selectedSearchFilter: currentFilter,
+    );
 
     try {
       final settings = ref.read(settingsProvider);
@@ -494,20 +568,23 @@ class TrackNotifier extends Notifier<TrackState> {
           searchProvider.isNotEmpty;
 
       final source = metadataSource ?? 'deezer';
-      
+
       _log.i(
         'Search started: source=$source, query="$query", useExtensions=$useExtensions, filter=$currentFilter',
       );
-      
+
       Map<String, dynamic> results;
       List<Track> extensionTracks = [];
-      
+
       if (useExtensions) {
         try {
           _log.d('Calling extension search API...');
-          final extResults = await PlatformBridge.searchTracksWithExtensions(query, limit: 20);
+          final extResults = await PlatformBridge.searchTracksWithExtensions(
+            query,
+            limit: 20,
+          );
           _log.i('Extensions returned ${extResults.length} tracks');
-          
+
           for (final t in extResults) {
             try {
               extensionTracks.add(_parseSearchTrack(t));
@@ -519,37 +596,52 @@ class TrackNotifier extends Notifier<TrackState> {
           _log.w('Extension search failed, falling back to built-in: $e');
         }
       }
-      
+
       if (source == 'deezer') {
         _log.d('Calling Deezer search API...');
-        results = await PlatformBridge.searchDeezerAll(query, trackLimit: 20, artistLimit: 2, filter: currentFilter);
+        results = await PlatformBridge.searchDeezerAll(
-        _log.i('Deezer returned ${(results['tracks'] as List?)?.length ?? 0} tracks, ${(results['artists'] as List?)?.length ?? 0} artists, ${(results['albums'] as List?)?.length ?? 0} albums');
+          query,
+          trackLimit: 20,
+          artistLimit: 2,
+          filter: currentFilter,
+        );
+        _log.i(
+          'Deezer returned ${(results['tracks'] as List?)?.length ?? 0} tracks, ${(results['artists'] as List?)?.length ?? 0} artists, ${(results['albums'] as List?)?.length ?? 0} albums',
+        );
       } else {
         _log.d('Calling Spotify search API...');
-        results = await PlatformBridge.searchSpotifyAll(query, trackLimit: 20, artistLimit: 2);
+        results = await PlatformBridge.searchSpotifyAll(
-        _log.i('Spotify returned ${(results['tracks'] as List?)?.length ?? 0} tracks, ${(results['artists'] as List?)?.length ?? 0} artists');
+          query,
+          trackLimit: 20,
+          artistLimit: 2,
+        );
+        _log.i(
+          'Spotify returned ${(results['tracks'] as List?)?.length ?? 0} tracks, ${(results['artists'] as List?)?.length ?? 0} artists',
+        );
       }
-      
+
       if (!_isRequestValid(requestId)) {
         _log.w('Search request cancelled (requestId=$requestId)');
         return;
       }
-      
+
       final trackList = results['tracks'] as List<dynamic>? ?? [];
       final artistList = results['artists'] as List<dynamic>? ?? [];
       final albumList = results['albums'] as List<dynamic>? ?? [];
-      
+
-      _log.d('Raw results: ${trackList.length} tracks, ${artistList.length} artists, ${albumList.length} albums');
+      _log.d(
-      
+        'Raw results: ${trackList.length} tracks, ${artistList.length} artists, ${albumList.length} albums',
+      );
+
       final tracks = <Track>[];
-      
+
       tracks.addAll(extensionTracks);
-      
+
       final existingIsrcs = extensionTracks
           .where((t) => t.isrc != null && t.isrc!.isNotEmpty)
           .map((t) => t.isrc!)
           .toSet();
-      
+
       for (int i = 0; i < trackList.length; i++) {
         final t = trackList[i];
         try {
@@ -566,7 +658,7 @@ class TrackNotifier extends Notifier<TrackState> {
           _log.e('Failed to parse track[$i]: $e', e);
         }
       }
-      
+
       final artists = <SearchArtist>[];
       for (int i = 0; i < artistList.length; i++) {
         final a = artistList[i];
@@ -580,7 +672,7 @@ class TrackNotifier extends Notifier<TrackState> {
           _log.e('Failed to parse artist[$i]: $e', e);
         }
       }
-      
+
       final albums = <SearchAlbum>[];
       for (int i = 0; i < albumList.length; i++) {
         final a = albumList[i];
@@ -594,7 +686,7 @@ class TrackNotifier extends Notifier<TrackState> {
           _log.e('Failed to parse album[$i]: $e', e);
         }
       }
-      
+
       final playlistList = results['playlists'] as List<dynamic>? ?? [];
       final playlists = <SearchPlaylist>[];
       for (int i = 0; i < playlistList.length; i++) {
@@ -609,9 +701,11 @@ class TrackNotifier extends Notifier<TrackState> {
           _log.e('Failed to parse playlist[$i]: $e', e);
         }
       }
-      
+
-      _log.i('Search complete: ${tracks.length} tracks (${extensionTracks.length} from extensions), ${artists.length} artists, ${albums.length} albums, ${playlists.length} playlists parsed successfully');
+      _log.i(
-      
+        'Search complete: ${tracks.length} tracks (${extensionTracks.length} from extensions), ${artists.length} artists, ${albums.length} albums, ${playlists.length} playlists parsed successfully',
+      );
+
       state = TrackState(
         tracks: tracks,
         searchArtists: artists,
@@ -624,31 +718,45 @@ class TrackNotifier extends Notifier<TrackState> {
     } catch (e, stackTrace) {
       if (!_isRequestValid(requestId)) return;
       _log.e('Search failed: $e', e, stackTrace);
-      state = TrackState(isLoading: false, error: e.toString(), hasSearchText: state.hasSearchText, selectedSearchFilter: currentFilter);
+      state = TrackState(
+        isLoading: false,
+        error: e.toString(),
+        hasSearchText: state.hasSearchText,
+        selectedSearchFilter: currentFilter,
+      );
     }
   }
 
-  Future<void> customSearch(String extensionId, String query, {Map<String, dynamic>? options}) async {
+  Future<void> customSearch(
+    String extensionId,
+    String query, {
+    Map<String, dynamic>? options,
+  }) async {
     final requestId = ++_currentRequestId;
 
     state = TrackState(
       isLoading: true,
       hasSearchText: state.hasSearchText,
-      selectedSearchFilter: state.selectedSearchFilter, // Preserve filter during loading
+      selectedSearchFilter:
+          state.selectedSearchFilter, // Preserve filter during loading
     );
 
     try {
       _log.i('Custom search started: extension=$extensionId, query="$query"');
-      
+
-      final results = await PlatformBridge.customSearchWithExtension(extensionId, query, options: options);
+      final results = await PlatformBridge.customSearchWithExtension(
-      
+        extensionId,
+        query,
+        options: options,
+      );
+
       if (!_isRequestValid(requestId)) {
         _log.w('Custom search request cancelled (requestId=$requestId)');
         return;
       }
-      
+
       _log.i('Custom search returned ${results.length} tracks');
-      
+
       final tracks = <Track>[];
       for (int i = 0; i < results.length; i++) {
         final t = results[i];
@@ -658,21 +766,28 @@ class TrackNotifier extends Notifier<TrackState> {
           _log.e('Failed to parse custom search track[$i]: $e', e);
         }
       }
-      
+
-      _log.i('Custom search complete: ${tracks.length} tracks parsed (source=$extensionId)');
+      _log.i(
-      
+        'Custom search complete: ${tracks.length} tracks parsed (source=$extensionId)',
+      );
+
       state = TrackState(
         tracks: tracks,
         searchArtists: [],
         isLoading: false,
         hasSearchText: state.hasSearchText,
         searchExtensionId: extensionId, // Store which extension was used
-        selectedSearchFilter: state.selectedSearchFilter, // Preserve selected filter
+        selectedSearchFilter:
+            state.selectedSearchFilter, // Preserve selected filter
       );
     } catch (e, stackTrace) {
       if (!_isRequestValid(requestId)) return;
       _log.e('Custom search failed: $e', e, stackTrace);
-      state = TrackState(isLoading: false, error: e.toString(), hasSearchText: state.hasSearchText);
+      state = TrackState(
+        isLoading: false,
+        error: e.toString(),
+        hasSearchText: state.hasSearchText,
+      );
     }
   }
 
@@ -683,7 +798,10 @@ class TrackNotifier extends Notifier<TrackState> {
     if (track.isrc == null || track.isrc!.isEmpty) return;
 
     try {
-      final availability = await PlatformBridge.checkAvailability(track.id, track.isrc!);
+      final availability = await PlatformBridge.checkAvailability(
+        track.id,
+        track.isrc!,
+      );
       final updatedTrack = Track(
         id: track.id,
         name: track.name,
@@ -736,11 +854,14 @@ class TrackNotifier extends Notifier<TrackState> {
     }
     state = state.copyWith(hasSearchText: hasText);
   }
-  
+
   void setShowingRecentAccess(bool showing) {
+    if (state.isShowingRecentAccess == showing) {
+      return;
+    }
     state = state.copyWith(isShowingRecentAccess: showing);
   }
-  
+
   /// Set tracks from a collection (album/playlist) opened from search results
   void setTracksFromCollection({
     required List<Track> tracks,
@@ -782,9 +903,9 @@ class TrackNotifier extends Notifier<TrackState> {
     } else if (durationValue is double) {
       durationMs = durationValue.toInt();
     }
-    
+
     final itemType = data['item_type']?.toString();
-    
+
     return Track(
       id: (data['spotify_id'] ?? data['id'] ?? '').toString(),
       name: (data['name'] ?? '').toString(),
@@ -797,7 +918,10 @@ class TrackNotifier extends Notifier<TrackState> {
       trackNumber: data['track_number'] as int?,
       discNumber: data['disc_number'] as int?,
       releaseDate: data['release_date']?.toString(),
-      source: source ?? data['source']?.toString() ?? data['provider_id']?.toString(),
+      source:
+          source ??
+          data['source']?.toString() ??
+          data['provider_id']?.toString(),
       albumType: data['album_type']?.toString(),
       itemType: itemType,
     );
@@ -849,16 +973,25 @@ class TrackNotifier extends Notifier<TrackState> {
   }
 
   void _preWarmCacheForTracks(List<Track> tracks) {
-    final tracksWithIsrc = tracks.where((t) => t.isrc != null && t.isrc!.isNotEmpty).toList();
+    if (tracks.isEmpty) return;
-    if (tracksWithIsrc.isEmpty) return;
+    final cacheRequests = <Map<String, String>>[];
-
+    for (final track in tracks) {
-    final cacheRequests = tracksWithIsrc.map((t) => {
+      final isrc = track.isrc;
-      'isrc': t.isrc!,
+      if (isrc == null || isrc.isEmpty) {
-      'track_name': t.name,
+        continue;
-      'artist_name': t.artistName,
+      }
-      'spotify_id': t.id, // Include Spotify ID for Amazon lookup
+      cacheRequests.add({
-      'service': 'tidal',
+        'isrc': isrc,
-    }).toList();
+        'track_name': track.name,
+        'artist_name': track.artistName,
+        'spotify_id': track.id, // Include Spotify ID for Amazon lookup
+        'service': 'tidal',
+      });
+      if (cacheRequests.length >= _maxPreWarmTracksPerRequest) {
+        break;
+      }
+    }
+    if (cacheRequests.isEmpty) return;
 
     PlatformBridge.preWarmTrackCache(cacheRequests).catchError((_) {});
   }

lib/screens/downloaded_album_screen.dart

@@ -34,6 +34,12 @@ class _DownloadedAlbumScreenState extends ConsumerState<DownloadedAlbumScreen> {
   final Set<String> _selectedIds = {};
   bool _showTitleInAppBar = false;
   final ScrollController _scrollController = ScrollController();
+  bool _embeddedCoverRefreshScheduled = false;
+  List<DownloadHistoryItem>? _albumTracksSourceCache;
+  List<DownloadHistoryItem>? _albumTracksCache;
+
+  String get _albumLookupKey =>
+      '${widget.albumName.toLowerCase()}|${widget.artistName.toLowerCase()}';
 
   @override
   void initState() {
@@ -48,6 +54,16 @@ class _DownloadedAlbumScreenState extends ConsumerState<DownloadedAlbumScreen> {
     super.dispose();
   }
 
+  @override
+  void didUpdateWidget(covariant DownloadedAlbumScreen oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    if (oldWidget.albumName != widget.albumName ||
+        oldWidget.artistName != widget.artistName) {
+      _albumTracksSourceCache = null;
+      _albumTracksCache = null;
+    }
+  }
+
   void _onScroll() {
     final shouldShow = _scrollController.offset > 280;
     if (shouldShow != _showTitleInAppBar) {
@@ -59,28 +75,36 @@ class _DownloadedAlbumScreenState extends ConsumerState<DownloadedAlbumScreen> {
   List<DownloadHistoryItem> _getAlbumTracks(
     List<DownloadHistoryItem> allItems,
   ) {
-    return allItems.where((item) {
+    final cached = _albumTracksCache;
-      // Use albumArtist if available and not empty, otherwise artistName
+    if (cached != null && identical(allItems, _albumTracksSourceCache)) {
-      final itemArtist =
+      return cached;
-          (item.albumArtist != null && item.albumArtist!.isNotEmpty)
+    }
-          ? item.albumArtist!
+
-          : item.artistName;
+    final tracks =
-      // Use lowercase for case-insensitive matching
+        allItems.where((item) {
-      final itemKey =
+          // Use albumArtist if available and not empty, otherwise artistName
-          '${item.albumName.toLowerCase()}|${itemArtist.toLowerCase()}';
+          final itemArtist =
-      final albumKey =
+              (item.albumArtist != null && item.albumArtist!.isNotEmpty)
-          '${widget.albumName.toLowerCase()}|${widget.artistName.toLowerCase()}';
+              ? item.albumArtist!
-      return itemKey == albumKey;
+              : item.artistName;
-    }).toList()..sort((a, b) {
+          // Use lowercase for case-insensitive matching
-      // Sort by disc number first, then by track number
+          final itemKey =
-      final aDisc = a.discNumber ?? 1;
+              '${item.albumName.toLowerCase()}|${itemArtist.toLowerCase()}';
-      final bDisc = b.discNumber ?? 1;
+          return itemKey == _albumLookupKey;
-      if (aDisc != bDisc) return aDisc.compareTo(bDisc);
+        }).toList()..sort((a, b) {
-      final aNum = a.trackNumber ?? 999;
+          // Sort by disc number first, then by track number
-      final bNum = b.trackNumber ?? 999;
+          final aDisc = a.discNumber ?? 1;
-      if (aNum != bNum) return aNum.compareTo(bNum);
+          final bDisc = b.discNumber ?? 1;
-      return a.trackName.compareTo(b.trackName);
+          if (aDisc != bDisc) return aDisc.compareTo(bDisc);
-    });
+          final aNum = a.trackNumber ?? 999;
+          final bNum = b.trackNumber ?? 999;
+          if (aNum != bNum) return aNum.compareTo(bNum);
+          return a.trackName.compareTo(b.trackName);
+        });
+
+    _albumTracksSourceCache = allItems;
+    _albumTracksCache = tracks;
+    return tracks;
   }
 
   Map<int, List<DownloadHistoryItem>> _groupTracksByDisc(
@@ -194,8 +218,14 @@ class _DownloadedAlbumScreenState extends ConsumerState<DownloadedAlbumScreen> {
   }
 
   void _onEmbeddedCoverChanged() {
-    if (!mounted) return;
+    if (!mounted || _embeddedCoverRefreshScheduled) return;
-    setState(() {});
+    _embeddedCoverRefreshScheduled = true;
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      _embeddedCoverRefreshScheduled = false;
+      if (mounted) {
+        setState(() {});
+      }
+    });
   }
 
   Future<void> _navigateToMetadataScreen(DownloadHistoryItem item) async {

lib/screens/home_tab.dart

@@ -35,18 +35,25 @@ class HomeTab extends ConsumerStatefulWidget {
 
 class _RecentAccessView {
   final List<RecentAccessItem> uniqueItems;
-  final List<RecentAccessItem> downloadItems;
+  final List<String> downloadIds;
   final Map<String, String> downloadFilePathByRecentKey;
   final bool hasHiddenDownloads;
 
   const _RecentAccessView({
     required this.uniqueItems,
-    required this.downloadItems,
+    required this.downloadIds,
     required this.downloadFilePathByRecentKey,
     required this.hasHiddenDownloads,
   });
 }
 
+class _RecentAlbumAggregate {
+  int count;
+  DownloadHistoryItem mostRecent;
+
+  _RecentAlbumAggregate({required this.count, required this.mostRecent});
+}
+
 class _CsvImportOptions {
   final bool confirmed;
   final bool skipDownloaded;
@@ -60,7 +67,6 @@ class _CsvImportOptions {
 class _HomeTabState extends ConsumerState<HomeTab>
     with AutomaticKeepAliveClientMixin, SingleTickerProviderStateMixin {
   final _urlController = TextEditingController();
-  bool _isTyping = false;
   final FocusNode _searchFocusNode = FocusNode();
   String? _lastSearchQuery;
   late final ProviderSubscription<TrackState> _trackStateSub;
@@ -77,6 +83,9 @@ class _HomeTabState extends ConsumerState<HomeTab>
   List<RecentAccessItem>? _recentAccessItemsCache;
   Set<String>? _recentAccessHiddenIdsCache;
   _RecentAccessView? _recentAccessViewCache;
+  bool _embeddedCoverRefreshScheduled = false;
+  List<Extension>? _thumbnailSizesExtensionsCache;
+  Map<String, (double, double)>? _thumbnailSizesCache;
 
   double _responsiveScale({
     required BuildContext context,
@@ -200,6 +209,27 @@ class _HomeTabState extends ConsumerState<HomeTab>
     super.dispose();
   }
 
+  Map<String, (double, double)> _getThumbnailSizesByExtensionId(
+    List<Extension> extensions,
+  ) {
+    final cached = _thumbnailSizesCache;
+    if (cached != null &&
+        identical(extensions, _thumbnailSizesExtensionsCache)) {
+      return cached;
+    }
+
+    final map = <String, (double, double)>{
+      for (final extension in extensions)
+        if (extension.searchBehavior != null)
+          extension.id: extension.searchBehavior!.getThumbnailSize(
+            defaultSize: 56,
+          ),
+    };
+    _thumbnailSizesExtensionsCache = extensions;
+    _thumbnailSizesCache = map;
+    return map;
+  }
+
   void _onSearchFocusChanged() {
     if (mounted) {
       setState(() {});
@@ -217,7 +247,6 @@ class _HomeTabState extends ConsumerState<HomeTab>
         _urlController.text.isNotEmpty &&
         !_searchFocusNode.hasFocus) {
       _urlController.clear();
-      setState(() => _isTyping = false);
     }
   }
 
@@ -240,10 +269,7 @@ class _HomeTabState extends ConsumerState<HomeTab>
 
     ref.read(trackProvider.notifier).setSearchText(text.isNotEmpty);
 
-    if (text.isNotEmpty && !_isTyping) {
+    if (text.isEmpty) {
-      setState(() => _isTyping = true);
-    } else if (text.isEmpty && _isTyping) {
-      setState(() => _isTyping = false);
       _liveSearchDebounce?.cancel();
       return;
     }
@@ -350,7 +376,6 @@ class _HomeTabState extends ConsumerState<HomeTab>
     _urlController.clear();
     _searchFocusNode.unfocus();
     _lastSearchQuery = null;
-    setState(() => _isTyping = false);
     ref.read(trackProvider.notifier).clear();
   }
 
@@ -390,7 +415,6 @@ class _HomeTabState extends ConsumerState<HomeTab>
       );
       ref.read(trackProvider.notifier).clear();
       _urlController.clear();
-      setState(() => _isTyping = false);
       return;
     }
 
@@ -416,7 +440,6 @@ class _HomeTabState extends ConsumerState<HomeTab>
       );
       ref.read(trackProvider.notifier).clear();
       _urlController.clear();
-      setState(() => _isTyping = false);
       return;
     }
 
@@ -438,7 +461,6 @@ class _HomeTabState extends ConsumerState<HomeTab>
       );
       ref.read(trackProvider.notifier).clear();
       _urlController.clear();
-      setState(() => _isTyping = false);
       return;
     }
   }
@@ -781,13 +803,9 @@ class _HomeTabState extends ConsumerState<HomeTab>
     );
     final showLocalLibraryIndicator =
         localLibrarySettings.$1 && localLibrarySettings.$2;
-    final thumbnailSizesByExtensionId = <String, (double, double)>{
+    final thumbnailSizesByExtensionId = _getThumbnailSizesByExtensionId(
-      for (final extension in extensions)
+      extensions,
-        if (extension.searchBehavior != null)
+    );
-          extension.id: extension.searchBehavior!.getThumbnailSize(
-            defaultSize: 56,
-          ),
-    };
     Extension? currentSearchExtension;
     List<SearchFilter> searchFilters = [];
 
@@ -1028,8 +1046,14 @@ class _HomeTabState extends ConsumerState<HomeTab>
   }
 
   void _onEmbeddedCoverChanged() {
-    if (!mounted) return;
+    if (!mounted || _embeddedCoverRefreshScheduled) return;
-    setState(() {});
+    _embeddedCoverRefreshScheduled = true;
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      _embeddedCoverRefreshScheduled = false;
+      if (mounted) {
+        setState(() {});
+      }
+    });
   }
 
   Widget _buildRecentDownloads(
@@ -1148,66 +1172,58 @@ class _HomeTabState extends ConsumerState<HomeTab>
       return cached;
     }
 
-    final albumGroups = <String, List<DownloadHistoryItem>>{};
+    final albumGroups = <String, _RecentAlbumAggregate>{};
     for (final h in historyItems) {
       final artistForKey = (h.albumArtist != null && h.albumArtist!.isNotEmpty)
           ? h.albumArtist!
           : h.artistName;
       final albumKey = '${h.albumName}|$artistForKey';
-      albumGroups.putIfAbsent(albumKey, () => []).add(h);
+      final existing = albumGroups[albumKey];
+      if (existing == null) {
+        albumGroups[albumKey] = _RecentAlbumAggregate(count: 1, mostRecent: h);
+      } else {
+        existing.count++;
+        if (h.downloadedAt.isAfter(existing.mostRecent.downloadedAt)) {
+          existing.mostRecent = h;
+        }
+      }
     }
 
-    final downloadItems = <RecentAccessItem>[];
+    final downloadIds = <String>[];
+    final visibleDownloads = <RecentAccessItem>[];
     final downloadFilePathByRecentKey = <String, String>{};
-    for (final entry in albumGroups.entries) {
+    for (final aggregate in albumGroups.values) {
-      final tracks = entry.value;
+      final mostRecent = aggregate.mostRecent;
-      final mostRecent = tracks.reduce(
-        (a, b) => a.downloadedAt.isAfter(b.downloadedAt) ? a : b,
-      );
       final artistForKey =
           (mostRecent.albumArtist != null && mostRecent.albumArtist!.isNotEmpty)
           ? mostRecent.albumArtist!
           : mostRecent.artistName;
 
-      if (tracks.length == 1) {
+      final isSingleTrack = aggregate.count == 1;
-        final recent = RecentAccessItem(
+      final recentId = isSingleTrack
-          id: mostRecent.spotifyId ?? mostRecent.id,
+          ? (mostRecent.spotifyId ?? mostRecent.id)
-          name: mostRecent.trackName,
+          : '${mostRecent.albumName}|$artistForKey';
-          subtitle: mostRecent.artistName,
+      final recent = RecentAccessItem(
-          imageUrl: mostRecent.coverUrl,
+        id: recentId,
-          type: RecentAccessType.track,
+        name: isSingleTrack ? mostRecent.trackName : mostRecent.albumName,
-          accessedAt: mostRecent.downloadedAt,
+        subtitle: isSingleTrack ? mostRecent.artistName : artistForKey,
-          providerId: 'download',
+        imageUrl: mostRecent.coverUrl,
-        );
+        type: isSingleTrack ? RecentAccessType.track : RecentAccessType.album,
-        downloadItems.add(recent);
+        accessedAt: mostRecent.downloadedAt,
-        downloadFilePathByRecentKey['${recent.type.name}:${recent.id}'] =
+        providerId: 'download',
-            mostRecent.filePath;
+      );
-      } else {
+
-        final recent = RecentAccessItem(
+      downloadIds.add(recentId);
-          id: '${mostRecent.albumName}|$artistForKey',
+      downloadFilePathByRecentKey['${recent.type.name}:${recent.id}'] =
-          name: mostRecent.albumName,
+          mostRecent.filePath;
-          subtitle: artistForKey,
+      if (!hiddenIds.contains(recentId)) {
-          imageUrl: mostRecent.coverUrl,
+        visibleDownloads.add(recent);
-          type: RecentAccessType.album,
-          accessedAt: mostRecent.downloadedAt,
-          providerId: 'download',
-        );
-        downloadItems.add(recent);
-        downloadFilePathByRecentKey['${recent.type.name}:${recent.id}'] =
-            mostRecent.filePath;
       }
     }
 
-    downloadItems.sort((a, b) => b.accessedAt.compareTo(a.accessedAt));
+    visibleDownloads.sort((a, b) => b.accessedAt.compareTo(a.accessedAt));
-
+    if (visibleDownloads.length > 10) {
-    final visibleDownloads = <RecentAccessItem>[];
+      visibleDownloads.removeRange(10, visibleDownloads.length);
-    for (final item in downloadItems) {
-      if (!hiddenIds.contains(item.id)) {
-        visibleDownloads.add(item);
-        if (visibleDownloads.length >= 10) {
-          break;
-        }
-      }
     }
 
     final allItems = <RecentAccessItem>[...items, ...visibleDownloads];
@@ -1227,7 +1243,7 @@ class _HomeTabState extends ConsumerState<HomeTab>
 
     final view = _RecentAccessView(
       uniqueItems: uniqueItems,
-      downloadItems: downloadItems,
+      downloadIds: downloadIds,
       downloadFilePathByRecentKey: downloadFilePathByRecentKey,
       hasHiddenDownloads: hiddenIds.isNotEmpty,
     );
@@ -1641,7 +1657,7 @@ class _HomeTabState extends ConsumerState<HomeTab>
 
   Widget _buildRecentAccess(_RecentAccessView view, ColorScheme colorScheme) {
     final uniqueItems = view.uniqueItems;
-    final downloadItems = view.downloadItems;
+    final downloadIds = view.downloadIds;
     final hasHiddenDownloads = view.hasHiddenDownloads;
 
     return Padding(
@@ -1661,10 +1677,10 @@ class _HomeTabState extends ConsumerState<HomeTab>
               if (uniqueItems.isNotEmpty)
                 TextButton(
                   onPressed: () {
-                    for (final item in downloadItems) {
+                    for (final id in downloadIds) {
                       ref
                           .read(recentAccessProvider.notifier)
-                          .hideDownloadFromRecents(item.id);
+                          .hideDownloadFromRecents(id);
                     }
                     ref.read(recentAccessProvider.notifier).clearHistory();
                   },

lib/screens/queue_tab.dart

@@ -228,6 +228,7 @@ Map<String, List<String>> _filterHistoryInIsolate(Map<String, Object> payload) {
   final entries = (payload['entries'] as List).cast<List>();
   final albumCounts = (payload['albumCounts'] as Map).cast<String, int>();
   final query = (payload['query'] as String?) ?? '';
+  final hasQuery = query.isNotEmpty;
 
   final allIds = <String>[];
   final albumIds = <String>[];
@@ -236,10 +237,11 @@ Map<String, List<String>> _filterHistoryInIsolate(Map<String, Object> payload) {
   for (final entry in entries) {
     final id = entry[0] as String;
     final albumKey = entry[1] as String;
-    final searchKey = entry[2] as String;
+    if (hasQuery) {
-
+      final searchKey = entry[2] as String;
-    if (query.isNotEmpty && !searchKey.contains(query)) {
+      if (!searchKey.contains(query)) {
-      continue;
+        continue;
+      }
     }
 
     allIds.add(id);
@@ -276,6 +278,8 @@ class _QueueTabState extends ConsumerState<QueueTab> {
   final ValueNotifier<bool> _alwaysMissingFileNotifier = ValueNotifier(false);
   final Set<String> _pendingChecks = {};
   static const int _maxCacheSize = 500;
+  static const int _maxSearchIndexCacheSize = 4000;
+  static const int _maxDownloadedEmbeddedCoverCacheSize = 180;
 
   bool _isSelectionMode = false;
   final Set<String> _selectedIds = {};
@@ -311,8 +315,6 @@ class _QueueTabState extends ConsumerState<QueueTab> {
   final Set<String> _pendingDownloadedCoverExtract = {};
   final Set<String> _pendingDownloadedCoverRefresh = {};
   final Set<String> _failedDownloadedCoverExtract = {};
-  Map<String, DownloadHistoryItem> _historyItemsById = {};
-  List<List<String>> _historyFilterEntries = const [];
   Map<String, List<DownloadHistoryItem>> _filteredHistoryCache = const {};
   List<DownloadHistoryItem>? _filterItemsCache;
   String _filterQueryCache = '';
@@ -407,32 +409,16 @@ class _QueueTabState extends ConsumerState<QueueTab> {
     _historyItemsCache = items;
     _localLibraryItemsCache = localItems;
     _historyStatsCache = _buildHistoryStats(items, localItems);
-    _searchIndexCache
+    if (historyChanged) {
-      ..clear()
+      _searchIndexCache.clear();
-      ..addEntries(
+    }
-        items.map((item) => MapEntry(item.id, _buildSearchKey(item))),
-      );
     if (localChanged) {
-      _localSearchIndexCache
+      _localSearchIndexCache.clear();
-        ..clear()
-        ..addEntries(
-          localItems.map(
-            (item) => MapEntry(item.id, _buildLocalSearchKey(item)),
-          ),
-        );
       _localFilterItemsCache = null;
       _localFilterQueryCache = '';
       _filteredLocalItemsCache = const [];
     }
     _unifiedItemsCache.clear();
-    _historyItemsById = {for (final item in items) item.id: item};
-    _historyFilterEntries = List<List<String>>.generate(items.length, (index) {
-      final item = items[index];
-      final searchKey = _searchIndexCache[item.id] ?? _buildSearchKey(item);
-      final albumKey =
-          '${item.albumName.toLowerCase()}|${(item.albumArtist ?? item.artistName).toLowerCase()}';
-      return [item.id, albumKey, searchKey];
-    }, growable: false);
 
     if (historyChanged) {
       final validPaths = items
@@ -459,6 +445,30 @@ class _QueueTabState extends ConsumerState<QueueTab> {
         .toLowerCase();
   }
 
+  String _historySearchKeyForItem(DownloadHistoryItem item) {
+    final cached = _searchIndexCache[item.id];
+    if (cached != null) return cached;
+
+    final searchKey = _buildSearchKey(item);
+    _searchIndexCache[item.id] = searchKey;
+    while (_searchIndexCache.length > _maxSearchIndexCacheSize) {
+      _searchIndexCache.remove(_searchIndexCache.keys.first);
+    }
+    return searchKey;
+  }
+
+  String _localSearchKeyForItem(LocalLibraryItem item) {
+    final cached = _localSearchIndexCache[item.id];
+    if (cached != null) return cached;
+
+    final searchKey = _buildLocalSearchKey(item);
+    _localSearchIndexCache[item.id] = searchKey;
+    while (_localSearchIndexCache.length > _maxSearchIndexCacheSize) {
+      _localSearchIndexCache.remove(_localSearchIndexCache.keys.first);
+    }
+    return searchKey;
+  }
+
   List<LocalLibraryItem> _filterLocalItems(
     List<LocalLibraryItem> items,
     String query,
@@ -471,11 +481,7 @@ class _QueueTabState extends ConsumerState<QueueTab> {
 
     final filtered = items
         .where((item) {
-          final searchKey =
+          final searchKey = _localSearchKeyForItem(item);
-              _localSearchIndexCache[item.id] ?? _buildLocalSearchKey(item);
-          if (!_localSearchIndexCache.containsKey(item.id)) {
-            _localSearchIndexCache[item.id] = searchKey;
-          }
           return searchKey.contains(query);
         })
         .toList(growable: false);
@@ -548,15 +554,26 @@ class _QueueTabState extends ConsumerState<QueueTab> {
     }
 
     final requestId = ++_filterRequestId;
+    final includeSearchKey = query.isNotEmpty;
+    final entries = List<List<String>>.generate(items.length, (index) {
+      final item = items[index];
+      final albumKey =
+          '${item.albumName.toLowerCase()}|${(item.albumArtist ?? item.artistName).toLowerCase()}';
+      if (!includeSearchKey) {
+        return [item.id, albumKey];
+      }
+      final searchKey = _historySearchKeyForItem(item);
+      return [item.id, albumKey, searchKey];
+    }, growable: false);
     final payload = <String, Object>{
-      'entries': _historyFilterEntries,
+      'entries': entries,
       'albumCounts': albumCounts,
       'query': query,
     };
 
     compute(_filterHistoryInIsolate, payload).then((result) {
       if (!mounted || requestId != _filterRequestId) return;
-      final itemsById = _historyItemsById;
+      final itemsById = {for (final item in items) item.id: item};
       final filtered = <String, List<DownloadHistoryItem>>{};
       for (final entry in result.entries) {
         filtered[entry.key] = entry.value
@@ -604,10 +621,7 @@ class _QueueTabState extends ConsumerState<QueueTab> {
     final query = searchQuery;
     return items
         .where((item) {
-          final searchKey = _searchIndexCache[item.id] ?? _buildSearchKey(item);
+          final searchKey = _historySearchKeyForItem(item);
-          if (!_searchIndexCache.containsKey(item.id)) {
-            _searchIndexCache[item.id] = searchKey;
-          }
           return searchKey.contains(query);
         })
         .toList(growable: false);
@@ -812,6 +826,18 @@ class _QueueTabState extends ConsumerState<QueueTab> {
     _cleanupTempCoverPathSync(cachedPath);
   }
 
+  void _trimDownloadedEmbeddedCoverCache() {
+    while (_downloadedEmbeddedCoverCache.length >
+        _maxDownloadedEmbeddedCoverCacheSize) {
+      final oldestKey = _downloadedEmbeddedCoverCache.keys.first;
+      final removedPath = _downloadedEmbeddedCoverCache.remove(oldestKey);
+      _pendingDownloadedCoverExtract.remove(oldestKey);
+      _pendingDownloadedCoverRefresh.remove(oldestKey);
+      _failedDownloadedCoverExtract.remove(oldestKey);
+      _cleanupTempCoverPathSync(removedPath);
+    }
+  }
+
   Future<int?> _readFileModTimeMillis(String? filePath) async {
     final cleanPath = _cleanFilePath(filePath);
     if (cleanPath.isEmpty) return null;
@@ -918,6 +944,7 @@ class _QueueTabState extends ConsumerState<QueueTab> {
         final previous = _downloadedEmbeddedCoverCache[cleanPath];
         _downloadedEmbeddedCoverCache[cleanPath] = outputPath;
         _failedDownloadedCoverExtract.remove(cleanPath);
+        _trimDownloadedEmbeddedCoverCache();
         if (previous != null && previous != outputPath) {
           _cleanupTempCoverPathSync(previous);
         }
@@ -1607,10 +1634,7 @@ class _QueueTabState extends ConsumerState<QueueTab> {
     if (searchQuery.isNotEmpty) {
       final query = searchQuery;
       filteredItems = items.where((item) {
-        final searchKey = _searchIndexCache[item.id] ?? _buildSearchKey(item);
+        final searchKey = _historySearchKeyForItem(item);
-        if (!_searchIndexCache.containsKey(item.id)) {
-          _searchIndexCache[item.id] = searchKey;
-        }
         return searchKey.contains(query);
       }).toList();
     }
@@ -1797,7 +1821,7 @@ class _QueueTabState extends ConsumerState<QueueTab> {
     _initializePageController();
 
     final hasQueueItems = ref.watch(
-      downloadQueueProvider.select((s) => s.items.isNotEmpty),
+      downloadQueueLookupProvider.select((lookup) => lookup.itemIds.isNotEmpty),
     );
     final allHistoryItems = ref.watch(
       downloadHistoryProvider.select((s) => s.items),
@@ -1825,6 +1849,14 @@ class _QueueTabState extends ConsumerState<QueueTab> {
         _buildHistoryStats(allHistoryItems, localLibraryItems);
     final groupedAlbums = historyStats.groupedAlbums;
     final groupedLocalAlbums = historyStats.groupedLocalAlbums;
+    final filteredGroupedAlbums = _filterGroupedAlbums(
+      groupedAlbums,
+      _searchQuery,
+    );
+    final filteredGroupedLocalAlbums = _filterGroupedLocalAlbums(
+      groupedLocalAlbums,
+      _searchQuery,
+    );
     final albumCount = historyStats.totalAlbumCount;
     final singleCount = historyStats.totalSingleTracks;
     final filterDataCache = <String, _FilterContentData>{};
@@ -1835,8 +1867,8 @@ class _QueueTabState extends ConsumerState<QueueTab> {
         () => _computeFilterContentData(
           filterMode: filterMode,
           allHistoryItems: allHistoryItems,
-          groupedAlbums: groupedAlbums,
+          filteredGroupedAlbums: filteredGroupedAlbums,
-          groupedLocalAlbums: groupedLocalAlbums,
+          filteredGroupedLocalAlbums: filteredGroupedLocalAlbums,
           albumCounts: historyStats.albumCounts,
           localAlbumCounts: historyStats.localAlbumCounts,
           localLibraryItems: localLibraryItems,
@@ -2227,8 +2259,8 @@ class _QueueTabState extends ConsumerState<QueueTab> {
   _FilterContentData _computeFilterContentData({
     required String filterMode,
     required List<DownloadHistoryItem> allHistoryItems,
-    required List<_GroupedAlbum> groupedAlbums,
+    required List<_GroupedAlbum> filteredGroupedAlbums,
-    required List<_GroupedLocalAlbum> groupedLocalAlbums,
+    required List<_GroupedLocalAlbum> filteredGroupedLocalAlbums,
     required Map<String, int> albumCounts,
     required Map<String, int> localAlbumCounts,
     required List<LocalLibraryItem> localLibraryItems,
@@ -2243,16 +2275,6 @@ class _QueueTabState extends ConsumerState<QueueTab> {
       filterMode: filterMode,
     );
 
-    final searchQuery = _searchQuery;
-    final filteredGroupedAlbums = _filterGroupedAlbums(
-      groupedAlbums,
-      searchQuery,
-    );
-    final filteredGroupedLocalAlbums = _filterGroupedLocalAlbums(
-      groupedLocalAlbums,
-      searchQuery,
-    );
-
     final unifiedItems = _getUnifiedItems(
       filterMode: filterMode,
       historyItems: historyItems,
@@ -2278,7 +2300,7 @@ class _QueueTabState extends ConsumerState<QueueTab> {
     return Consumer(
       builder: (context, ref, child) {
         final queueCount = ref.watch(
-          downloadQueueProvider.select((s) => s.items.length),
+          downloadQueueLookupProvider.select((lookup) => lookup.itemIds.length),
         );
         if (queueCount == 0) {
           return const SliverToBoxAdapter(child: SizedBox.shrink());
@@ -2310,10 +2332,8 @@ class _QueueTabState extends ConsumerState<QueueTab> {
     return Consumer(
       builder: (context, ref, child) {
         final queueIdsSnapshot = ref.watch(
-          downloadQueueProvider.select(
+          downloadQueueLookupProvider.select(
-            (s) => _QueueItemIdsSnapshot(
+            (lookup) => _QueueItemIdsSnapshot(lookup.itemIds),
-              s.items.map((item) => item.id).toList(growable: false),
-            ),
           ),
         );
         if (queueIdsSnapshot.ids.isEmpty) {
@@ -4011,14 +4031,7 @@ class _QueueItemSliverRow extends ConsumerWidget {
   @override
   Widget build(BuildContext context, WidgetRef ref) {
     final item = ref.watch(
-      downloadQueueProvider.select((state) {
+      downloadQueueLookupProvider.select((lookup) => lookup.byItemId[itemId]),
-        for (final current in state.items) {
-          if (current.id == itemId) {
-            return current;
-          }
-        }
-        return null;
-      }),
     );
     if (item == null) {
       return const SizedBox.shrink();

lib/utils/logger.dart

@@ -8,6 +8,27 @@ import 'package:spotiflac_android/constants/app_info.dart';
 import 'package:spotiflac_android/services/platform_bridge.dart';
 
 const int _maxLogMessageLength = 500;
+const String _redactedValue = '[REDACTED]';
+
+final RegExp _authorizationBearerPattern = RegExp(
+  r'\bAuthorization\b\s*[:=]\s*Bearer\s+[A-Za-z0-9._~+/\-]+=*',
+  caseSensitive: false,
+);
+
+final RegExp _genericSensitiveKeyValuePattern = RegExp(
+  r'\b(access[_\s-]?token|refresh[_\s-]?token|id[_\s-]?token|client[_\s-]?secret|authorization|password|api[_\s-]?key)\b(\s*[:=]\s*)([^\s,;]+)',
+  caseSensitive: false,
+);
+
+final RegExp _sensitiveQueryPattern = RegExp(
+  r'([?&](?:access_token|refresh_token|id_token|token|client_secret|api_key|apikey|password)=)[^&\s]+',
+  caseSensitive: false,
+);
+
+final RegExp _bearerTokenPattern = RegExp(
+  r'\bBearer\s+[A-Za-z0-9._~+/\-]+=*',
+  caseSensitive: false,
+);
 
 String _truncateLogText(String value, {int maxLength = _maxLogMessageLength}) {
   if (value.length <= maxLength) {
@@ -16,6 +37,39 @@ String _truncateLogText(String value, {int maxLength = _maxLogMessageLength}) {
   return '${value.substring(0, maxLength)}...[truncated]';
 }
 
+String _redactSensitiveText(String value) {
+  var redacted = value;
+
+  redacted = redacted.replaceAllMapped(_authorizationBearerPattern, (_) {
+    return 'Authorization: Bearer $_redactedValue';
+  });
+
+  redacted = redacted.replaceAllMapped(_genericSensitiveKeyValuePattern, (
+    match,
+  ) {
+    final key = match.group(1) ?? '';
+    final delimiter = match.group(2) ?? '=';
+    return '$key$delimiter$_redactedValue';
+  });
+
+  redacted = redacted.replaceAllMapped(_sensitiveQueryPattern, (match) {
+    final prefix = match.group(1) ?? '';
+    return '$prefix$_redactedValue';
+  });
+
+  redacted = redacted.replaceAllMapped(_bearerTokenPattern, (_) {
+    return 'Bearer $_redactedValue';
+  });
+
+  return redacted;
+}
+
+String _maskIdentifier(String value) {
+  if (value.isEmpty) return value;
+  if (value.length <= 4) return '***';
+  return '${value.substring(0, 2)}***${value.substring(value.length - 2)}';
+}
+
 class LogEntry {
   final DateTime timestamp;
   final String level;
@@ -59,6 +113,7 @@ class LogBuffer extends ChangeNotifier {
   final Queue<LogEntry> _entries = Queue<LogEntry>();
   Timer? _goLogTimer;
   int _lastGoLogIndex = 0;
+  bool _isFetchingGoLogs = false;
 
   static bool _loggingEnabled = false;
   static bool get loggingEnabled => _loggingEnabled;
@@ -79,9 +134,11 @@ class LogBuffer extends ChangeNotifier {
       return;
     }
 
-    final sanitizedMessage = _truncateLogText(entry.message);
+    final sanitizedMessage = _truncateLogText(
+      _redactSensitiveText(entry.message),
+    );
     final sanitizedError = entry.error != null
-        ? _truncateLogText(entry.error!)
+        ? _truncateLogText(_redactSensitiveText(entry.error!))
         : null;
     final sanitizedEntry =
         (sanitizedMessage == entry.message && sanitizedError == entry.error)
@@ -105,13 +162,20 @@ class LogBuffer extends ChangeNotifier {
   void startGoLogPolling() {
     _goLogTimer?.cancel();
     _goLogTimer = Timer.periodic(_goLogPollingInterval, (_) async {
-      await _fetchGoLogs();
+      if (_isFetchingGoLogs) return;
+      _isFetchingGoLogs = true;
+      try {
+        await _fetchGoLogs();
+      } finally {
+        _isFetchingGoLogs = false;
+      }
     });
   }
 
   void stopGoLogPolling() {
     _goLogTimer?.cancel();
     _goLogTimer = null;
+    _isFetchingGoLogs = false;
   }
 
   Future<void> _fetchGoLogs() async {
@@ -216,7 +280,7 @@ class LogBuffer extends ChangeNotifier {
         buffer.writeln(
           'Android Version: ${android.version.release} (SDK ${android.version.sdkInt})',
         );
-        buffer.writeln('Device ID: ${android.id}');
+        buffer.writeln('Device ID: ${_maskIdentifier(android.id)}');
         buffer.writeln('Hardware: ${android.hardware}');
         buffer.writeln('Product: ${android.product}');
         buffer.writeln('Supported ABIs: ${android.supportedAbis.join(', ')}');
@@ -313,12 +377,14 @@ class BufferedOutput extends LogOutput {
   void output(OutputEvent event) {
     if (kDebugMode) {
       for (final line in event.lines) {
-        debugPrint(_truncateLogText(line));
+        debugPrint(_truncateLogText(_redactSensitiveText(line)));
       }
     }
 
     final level = _levelToString(event.level);
-    final message = _truncateLogText(event.lines.join('\n'));
+    final message = _truncateLogText(
+      _redactSensitiveText(event.lines.join('\n')),
+    );
 
     LogBuffer().add(
       LogEntry(
@@ -421,7 +487,7 @@ class AppLogger {
       _addToBuffer('ERROR', message, error: error.toString());
       if (kDebugMode) {
         debugPrint(
-          '[$_tag] ERROR: ${_truncateLogText(message)} | ${_truncateLogText(error.toString())}',
+          '[$_tag] ERROR: ${_truncateLogText(_redactSensitiveText(message))} | ${_truncateLogText(_redactSensitiveText(error.toString()))}',
         );
         if (stackTrace != null) {
           debugPrint(stackTrace.toString());