feat: persist codec format and bitrate in download history

Bump the history schema on both the Kotlin finalizer and the Dart database to v9, adding bitrate (kbps) and format (codec label) columns, and let the download flow fill them from backend/probe metadata so lossy downloads keep a 'AAC 256kbps' label instead of falling back to the stored placeholder. Library filtering and the track metadata screen now read format/bitrate directly from those columns, which also fixes mis-tagged quality badges after re-downloading a track at a different format.

Additional fixes bundled in: EditFileMetadata now routes ReplayGain writes through the M4A path whenever the file starts with ftyp (fixing .flac files that actually hold MP4 containers); GetM4AQuality falls back to the first trak/mdia/mdhd duration when mvhd is zero so EAC3 streams no longer report 0s; and both Kotlin and Dart reject bitrate values below 16 kbps to prevent probe noise from surfacing as '0 kbps' labels. New unit tests cover the EAC3 mdhd fallback and the mis-named M4A replaygain path.

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

@@ -30,7 +30,7 @@ object NativeDownloadFinalizer {
     const val NATIVE_WORKER_CONTRACT_VERSION = 1
     // Native finalizer owns background-safe history writes while Flutter may be suspended.
     // Keep this schema contract in sync with Dart HistoryDatabase before bumping either side.
-    private const val HISTORY_SCHEMA_VERSION = 8
+    private const val HISTORY_SCHEMA_VERSION = 9
     private val activeFFmpegSessionIds = mutableSetOf<Long>()
     private val nativeFFmpegSessionIds = mutableSetOf<Long>()
     private val activeFFmpegSessionLock = Any()
@@ -73,6 +73,8 @@ object NativeDownloadFinalizer {
         "quality",
         "bit_depth",
         "sample_rate",
+        "bitrate",
+        "format",
         "genre",
         "composer",
         "label",
@@ -177,6 +179,9 @@ object NativeDownloadFinalizer {
             sampleRate = optPositiveInt(result, "actual_sample_rate"),
             bitrateKbps = optPositiveBitrateKbps(result, "bitrate")
                 ?: optPositiveBitrateKbps(result, "actual_bitrate"),
+            audioCodec = normalizeAudioCodec(
+                result.optString("audio_codec", "").ifBlank { result.optString("format", "") },
+            ),
         )
 
         try {
@@ -676,7 +681,7 @@ object NativeDownloadFinalizer {
             }
             val bitrateKbps = optPositiveBitrateKbps(metadata, "bitrate")
                 ?: optPositiveBitrateKbps(metadata, "bit_rate")
-            if (bitrateKbps != null) {
+            if (bitrateKbps != null && isLossyAudioCodec(state.audioCodec)) {
                 state.bitrateKbps = bitrateKbps
                 result.put("bitrate", bitrateKbps)
             }
@@ -737,7 +742,7 @@ object NativeDownloadFinalizer {
             format == "AC4" ||
             (format == "M4A" && (bitDepth == null || bitDepth <= 0))
         ) {
-            return if (bitrateKbps != null && bitrateKbps > 0) {
+            return if (bitrateKbps != null && bitrateKbps >= 16) {
                 "$format ${bitrateKbps}kbps"
             } else {
                 nonPlaceholderQuality(storedQuality) ?: format
@@ -767,6 +772,13 @@ object NativeDownloadFinalizer {
         }
     }
 
+    private fun isLossyAudioCodec(codec: String?): Boolean {
+        return when (normalizeAudioCodec(codec)) {
+            "aac", "eac3", "ac3", "ac4", "mp3", "opus", "m4a" -> true
+            else -> false
+        }
+    }
+
     private fun normalizeAudioCodec(codec: String?): String? {
         val normalized = normalizeOptional(codec)
             ?.lowercase(Locale.ROOT)
@@ -777,6 +789,8 @@ object NativeDownloadFinalizer {
             "ec_3" -> "eac3"
             "ac_3" -> "ac3"
             "ac_4" -> "ac4"
+            "mp4" -> "m4a"
+            "ogg" -> "opus"
             else -> normalized
         }
     }
@@ -796,6 +810,11 @@ object NativeDownloadFinalizer {
 
     private fun nonPlaceholderQuality(quality: String?): String? {
         val normalized = normalizeOptional(quality) ?: return null
+        val bitrateMatch = Regex("\\b(\\d+)\\s*kbps\\b", RegexOption.IGNORE_CASE).find(normalized)
+        if (bitrateMatch != null) {
+            val bitrate = bitrateMatch.groupValues.getOrNull(1)?.toIntOrNull()
+            if (bitrate != null && bitrate < 16) return null
+        }
         val key = normalized.lowercase(Locale.ROOT).replace(Regex("[^a-z0-9]+"), "_").trim('_')
         val placeholders = setOf(
             "best",
@@ -1654,6 +1673,10 @@ object NativeDownloadFinalizer {
         values.put("quality", state.quality)
         state.bitDepth?.let { values.put("bit_depth", it) }
         state.sampleRate?.let { values.put("sample_rate", it) }
+        state.bitrateKbps?.takeIf { it >= 16 && isLossyAudioCodec(state.audioCodec) }?.let {
+            values.put("bitrate", it)
+        }
+        normalizeAudioCodec(state.audioCodec)?.let { values.put("format", it) }
         values.put("genre", normalizeOptional(result.optString("genre", "").ifBlank { input.request.optString("genre", "") }))
         values.put("composer", normalizeOptional(resultString(input, "composer").ifBlank { trackString(input, "composer", requestString(input, "composer")) }))
         values.put("label", normalizeOptional(result.optString("label", "").ifBlank { input.request.optString("label", "") }))
@@ -1710,6 +1733,8 @@ object NativeDownloadFinalizer {
                       quality TEXT,
                       bit_depth INTEGER,
                       sample_rate INTEGER,
+                      bitrate INTEGER,
+                      format TEXT,
                       genre TEXT,
                       composer TEXT,
                       label TEXT,
@@ -1725,6 +1750,8 @@ object NativeDownloadFinalizer {
 	                ensureHistoryColumn(db, "composer", "ALTER TABLE history ADD COLUMN composer TEXT")
 	                ensureHistoryColumn(db, "total_tracks", "ALTER TABLE history ADD COLUMN total_tracks INTEGER")
 	                ensureHistoryColumn(db, "total_discs", "ALTER TABLE history ADD COLUMN total_discs INTEGER")
+	                ensureHistoryColumn(db, "bitrate", "ALTER TABLE history ADD COLUMN bitrate INTEGER")
+	                ensureHistoryColumn(db, "format", "ALTER TABLE history ADD COLUMN format TEXT")
 	                ensureHistoryColumn(db, "spotify_id_norm", "ALTER TABLE history ADD COLUMN spotify_id_norm TEXT")
 	                ensureHistoryColumn(db, "isrc_norm", "ALTER TABLE history ADD COLUMN isrc_norm TEXT")
 	                ensureHistoryColumn(db, "match_key", "ALTER TABLE history ADD COLUMN match_key TEXT")
@@ -2096,6 +2123,8 @@ object NativeDownloadFinalizer {
         putCamel("quality", "quality")
         putCamel("bit_depth", "bitDepth")
         putCamel("sample_rate", "sampleRate")
+        putCamel("bitrate", "bitrate")
+        putCamel("format", "format")
         putCamel("genre", "genre")
         putCamel("composer", "composer")
         putCamel("label", "label")
@@ -2127,11 +2156,12 @@ object NativeDownloadFinalizer {
 
     private fun optPositiveBitrateKbps(obj: JSONObject, key: String): Int? {
         val value = optPositiveInt(obj, key) ?: return null
-        return if (value >= 10000) {
+        val kbps = if (value >= 10000) {
             Math.round(value / 1000.0).toInt()
         } else {
             value
         }
+        return if (kbps >= 16) kbps else null
     }
 
     private fun positiveOrNull(primary: Int, fallback: Int): Int? {