refactor(core): reduce generated and duplicate code

.gitignore

@@ -29,6 +29,9 @@ AGENTS.md
 *.aab
 *.ipa
 
+# Generated by Flutter from lib/l10n/arb during pub get/build.
+/lib/l10n/app_localizations*.dart
+
 # Local JavaScript tooling (the app itself has no Node dependency)
 /node_modules/
 /bun.lock

go_backend/extension_lifecycle_signed_session_timeout_test.go

@@ -118,16 +118,11 @@ func TestLifecycleTimeoutQuarantinesUnresponsiveCleanupVM(t *testing.T) {
 
 func TestSignedSessionGrantRetryHonorsCancellationAndReleasesCoordinator(t *testing.T) {
 	previousWait := signedSessionRetryWaitContext
-	previousLegacyWait := signedSessionRetryWait
-	signedSessionRetryWait = nil
 	signedSessionRetryWaitContext = func(ctx context.Context, _ time.Duration) error {
 		<-ctx.Done()
 		return ctx.Err()
 	}
-	t.Cleanup(func() {
-		signedSessionRetryWait = previousLegacyWait
-		signedSessionRetryWaitContext = previousWait
-	})
+	t.Cleanup(func() { signedSessionRetryWaitContext = previousWait })
 
 	var calls atomic.Int32
 	transport := roundTripFunc(func(req *http.Request) (*http.Response, error) {

go_backend/extension_runtime.go

@@ -780,10 +780,6 @@ func (r *extensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	logObj.Set("error", r.logError)
 	vm.Set("log", logObj)
 
-	gobackendObj := vm.NewObject()
-	gobackendObj.Set("sanitizeFilename", r.sanitizeFilenameWrapper)
-	vm.Set("gobackend", gobackendObj)
-
 	vm.Set("fetch", r.fetchPolyfill)
 
 	vm.Set("atob", r.atobPolyfill)

go_backend/extension_runtime_supplement_test.go

@@ -1144,9 +1144,6 @@ func TestExtensionRuntimeUtilityAPIs(t *testing.T) {
 	runtime.logInfo(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("info")}})
 	runtime.logWarn(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("warn")}})
 	runtime.logError(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("error")}})
-	if clean := runtime.sanitizeFilenameWrapper(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("A/B?")}}).String(); strings.ContainsAny(clean, "/?") {
-		t.Fatalf("sanitize wrapper = %q", clean)
-	}
 }
 
 func TestClassifySignedSessionExpiredAsVerification(t *testing.T) {

go_backend/extension_runtime_utils.go

@@ -372,14 +372,6 @@ func (r *extensionRuntime) formatLogArgs(args []goja.Value) string {
 	return strings.Join(parts, " ")
 }
 
-func (r *extensionRuntime) sanitizeFilenameWrapper(call goja.FunctionCall) goja.Value {
-	if len(call.Arguments) < 1 {
-		return r.vm.ToValue("")
-	}
-	input := call.Arguments[0].String()
-	return r.vm.ToValue(sanitizeFilename(input))
-}
-
 func (r *extensionRuntime) RegisterGoBackendAPIs(vm *goja.Runtime) {
 	gobackendObj := vm.Get("gobackend")
 	if gobackendObj == nil || goja.IsUndefined(gobackendObj) {

go_backend/extension_signed_session.go

@@ -36,13 +36,9 @@ const (
 )
 
 var (
-	pendingSignedSessionGrants   = make(map[string]string)
-	pendingSignedSessionGrantsMu sync.Mutex
-	signedSessionCoordinators    sync.Map
-	// signedSessionRetryWait is retained as a test hook for callers that used
-	// the old duration-only seam. Production waits use the context-aware hook
-	// below; a non-nil legacy hook short-circuits the delay in tests.
-	signedSessionRetryWait        func(time.Duration)
+	pendingSignedSessionGrants    = make(map[string]string)
+	pendingSignedSessionGrantsMu  sync.Mutex
+	signedSessionCoordinators     sync.Map
 	signedSessionRetryWaitContext = sleepRetry
 	signedSessionProviderWait     = sleepRetry
 	signedSessionRequestNow       = time.Now
@@ -654,22 +650,6 @@ func waitSignedSessionRetry(ctx context.Context, delay time.Duration) error {
 	if ctx == nil {
 		ctx = context.Background()
 	}
-	// Keep the old duration-only hook useful for existing package tests without
-	// allowing production to fall back to an uninterruptible time.Sleep. The
-	// default hook is nil; tests install an immediate recorder/no-op here.
-	if legacyWait := signedSessionRetryWait; legacyWait != nil {
-		done := make(chan struct{})
-		go func() {
-			legacyWait(delay)
-			close(done)
-		}()
-		select {
-		case <-done:
-			return nil
-		case <-ctx.Done():
-			return ctx.Err()
-		}
-	}
 	return signedSessionRetryWaitContext(ctx, delay)
 }
 

go_backend/extension_signed_session_test.go

@@ -1836,12 +1836,13 @@ func TestExchangeSignedSessionGrant(t *testing.T) {
 		pendingSignedSessionGrantsMu.Lock()
 		pendingSignedSessionGrants = make(map[string]string)
 		pendingSignedSessionGrantsMu.Unlock()
-		previousWait := signedSessionRetryWait
+		previousWait := signedSessionRetryWaitContext
 		var waits []time.Duration
-		signedSessionRetryWait = func(delay time.Duration) {
+		signedSessionRetryWaitContext = func(_ context.Context, delay time.Duration) error {
 			waits = append(waits, delay)
+			return nil
 		}
-		t.Cleanup(func() { signedSessionRetryWait = previousWait })
+		t.Cleanup(func() { signedSessionRetryWaitContext = previousWait })
 
 		calls := 0
 		transport := roundTripFunc(func(req *http.Request) (*http.Response, error) {
@@ -1895,9 +1896,11 @@ func TestExchangeSignedSessionGrant(t *testing.T) {
 		pendingSignedSessionGrantsMu.Lock()
 		pendingSignedSessionGrants = make(map[string]string)
 		pendingSignedSessionGrantsMu.Unlock()
-		previousWait := signedSessionRetryWait
-		signedSessionRetryWait = func(time.Duration) {}
-		t.Cleanup(func() { signedSessionRetryWait = previousWait })
+		previousWait := signedSessionRetryWaitContext
+		signedSessionRetryWaitContext = func(context.Context, time.Duration) error {
+			return nil
+		}
+		t.Cleanup(func() { signedSessionRetryWaitContext = previousWait })
 
 		calls := 0
 		transport := roundTripFunc(func(req *http.Request) (*http.Response, error) {

lib/services/cover_cache_manager.dart

@@ -216,16 +216,4 @@ class CacheStats {
   final int totalSizeBytes;
 
   const CacheStats({required this.fileCount, required this.totalSizeBytes});
-
-  String get formattedSize {
-    if (totalSizeBytes < 1024) {
-      return '$totalSizeBytes B';
-    } else if (totalSizeBytes < 1024 * 1024) {
-      return '${(totalSizeBytes / 1024).toStringAsFixed(1)} KB';
-    } else if (totalSizeBytes < 1024 * 1024 * 1024) {
-      return '${(totalSizeBytes / (1024 * 1024)).toStringAsFixed(1)} MB';
-    } else {
-      return '${(totalSizeBytes / (1024 * 1024 * 1024)).toStringAsFixed(2)} GB';
-    }
-  }
 }

lib/services/history_database.dart

@@ -4,6 +4,7 @@ import 'package:sqflite/sqflite.dart';
 import 'package:path_provider/path_provider.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 import 'package:spotiflac_android/services/sqlite_helpers.dart' as sqlite;
+import 'package:spotiflac_android/utils/isrc_utils.dart' as isrc;
 import 'package:spotiflac_android/utils/logger.dart';
 import 'package:spotiflac_android/utils/path_match_keys.dart';
 
@@ -286,9 +287,7 @@ class HistoryDatabase {
   static String normalizeLookupText(String? value) =>
       sqlite.normalizeLookupText(value);
 
-  static String normalizeIsrc(String? value) {
-    return (value ?? '').trim().toUpperCase().replaceAll(RegExp(r'[-\s]'), '');
-  }
+  static String normalizeIsrc(String? value) => isrc.normalizeIsrc(value);
 
   static String normalizeSpotifyId(String? value) {
     return (value ?? '').trim().toLowerCase();

lib/services/library_database_models.dart

@@ -240,8 +240,6 @@ class LocalLibrarySource {
 
 enum LocalLibrarySortMode { album, title, artist, latest, quality }
 
-enum LocalLibraryFilterMode { all, albums, singles }
-
 class LocalLibraryLookupIndex {
   final Set<String> isrcs;
   final Set<String> matchKeys;

lib/widgets/cached_cover_image.dart

@@ -254,13 +254,3 @@ void precacheCoverImage(BuildContext context, String? url) {
     context,
   );
 }
-
-int coverImageCacheExtent(
-  BuildContext context,
-  double logicalSize, {
-  int min = 64,
-  int max = 512,
-}) {
-  final dpr = MediaQuery.devicePixelRatioOf(context).clamp(1.0, 3.0).toDouble();
-  return (logicalSize * dpr).round().clamp(min, max).toInt();
-}