v2.1.5: Fix progress bar and incomplete downloads

- Fix progress bar jumping from 1% to 100% (threshold-based updates)
- Fix incomplete downloads with temp file + size validation
- Applies to Tidal, Qobuz, and Amazon services

lib/constants/app_info.dart

@@ -1,8 +1,8 @@
 /// App version and info constants
 /// Update version here only - all other files will reference this
 class AppInfo {
-  static const String version = '2.1.5-preview';
-  static const String buildNumber = '42';
+  static const String version = '2.1.5';
+  static const String buildNumber = '43';
   static const String fullVersion = '$version+$buildNumber';
   
   

lib/providers/settings_provider.dart

@@ -5,6 +5,8 @@ import 'package:spotiflac_android/models/settings.dart';
 import 'package:spotiflac_android/services/platform_bridge.dart';
 
 const _settingsKey = 'app_settings';
+const _migrationVersionKey = 'settings_migration_version';
+const _currentMigrationVersion = 1; // Increment this when adding new migrations
 
 class SettingsNotifier extends Notifier<AppSettings> {
   @override
@@ -18,11 +20,32 @@ class SettingsNotifier extends Notifier<AppSettings> {
     final json = prefs.getString(_settingsKey);
     if (json != null) {
       state = AppSettings.fromJson(jsonDecode(json));
+      
+      // Run migrations if needed
+      await _runMigrations(prefs);
+      
       // Apply Spotify credentials to Go backend on load
       _applySpotifyCredentials();
     }
   }
 
+  /// Run one-time migrations for settings
+  Future<void> _runMigrations(SharedPreferences prefs) async {
+    final lastMigration = prefs.getInt(_migrationVersionKey) ?? 0;
+    
+    if (lastMigration < 1) {
+      // Migration 1: Set metadataSource to 'deezer' for existing users
+      // This ensures users updating from older versions get Deezer as default
+      state = state.copyWith(metadataSource: 'deezer');
+      await _saveSettings();
+    }
+    
+    // Save current migration version
+    if (lastMigration < _currentMigrationVersion) {
+      await prefs.setInt(_migrationVersionKey, _currentMigrationVersion);
+    }
+  }
+
   Future<void> _saveSettings() async {
     final prefs = await SharedPreferences.getInstance();
     await prefs.setString(_settingsKey, jsonEncode(state.toJson()));