perf(startup): bootstrap persisted app state

lib/providers/runtime_profile_provider.dart

@@ -4,3 +4,7 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 /// main.dart via a ProviderScope override). UI uses it to skip expensive
 /// effects like the shell's backdrop blur.
 final lowEndDeviceProvider = Provider<bool>((ref) => false);
+
+/// Generic visual capability decided by the startup runtime profile. Effects
+/// can consume this without hardcoding a device model or platform source.
+final backdropBlurEnabledProvider = Provider<bool>((ref) => false);

lib/providers/settings_provider.dart

@@ -19,6 +19,25 @@ const _spotifyClientSecretKey = 'spotify_client_secret';
 const _retiredBuiltInProviderIds = {'deezer', 'qobuz', 'tidal', 'youtube'};
 final _log = AppLogger('SettingsProvider');
 
+/// Startup override used to render the correct route/locale on the first
+/// frame. The notifier still performs migrations and full validation after it
+/// mounts.
+final initialSettingsProvider = Provider<AppSettings>(
+  (ref) => const AppSettings(),
+);
+
+AppSettings loadBootstrapSettings(SharedPreferences prefs) {
+  final rawSettings = prefs.getString(_settingsKey);
+  if (rawSettings == null || rawSettings.isEmpty) return const AppSettings();
+  try {
+    final decoded = jsonDecode(rawSettings);
+    if (decoded is! Map) return const AppSettings();
+    return AppSettings.fromJson(Map<String, dynamic>.from(decoded));
+  } catch (_) {
+    return const AppSettings();
+  }
+}
+
 class SettingsNotifier extends Notifier<AppSettings> {
   static final RegExp _isoRegionPattern = RegExp(r'^[A-Z]{2}$');
   static const Set<String> _searchTabValues = {
@@ -41,8 +60,8 @@ class SettingsNotifier extends Notifier<AppSettings> {
 
   @override
   AppSettings build() {
-    _loadSettings();
-    return const AppSettings();
+    unawaited(_loadSettings());
+    return ref.read(initialSettingsProvider);
   }
 
   Future<void> _loadSettings() async {

lib/providers/theme_provider.dart

@@ -3,6 +3,19 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 import 'package:spotiflac_android/models/theme_settings.dart';
 
+final initialThemeSettingsProvider = Provider<ThemeSettings>(
+  (ref) => const ThemeSettings(),
+);
+
+ThemeSettings loadBootstrapThemeSettings(SharedPreferences prefs) {
+  return ThemeSettings(
+    themeMode: themeModeFromString(prefs.getString(kThemeModeKey)),
+    useDynamicColor: prefs.getBool(kUseDynamicColorKey) ?? true,
+    seedColorValue: prefs.getInt(kSeedColorKey) ?? kDefaultSeedColor,
+    useAmoled: prefs.getBool(kUseAmoledKey) ?? false,
+  );
+}
+
 final themeProvider = NotifierProvider<ThemeNotifier, ThemeSettings>(() {
   return ThemeNotifier();
 });
@@ -13,7 +26,7 @@ class ThemeNotifier extends Notifier<ThemeSettings> {
   @override
   ThemeSettings build() {
     _loadFromStorage();
-    return const ThemeSettings();
+    return ref.read(initialThemeSettingsProvider);
   }
 
   Future<void> _loadFromStorage() async {