feat: modo dia/noche y campana de notificaciones

- ThemeProvider con persistencia en SharedPreferences
- Toggle animado en sidebar (sol/luna con switch visual)
- Temas light y dark completos en MaterialApp
- Campana en navbar con badge rojo y panel inferior de notificaciones

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/main.dart

@@ -15,6 +15,7 @@ import 'package:prosapp_web_app/providers/score_provider.dart';
 import 'package:prosapp_web_app/providers/services_provider.dart';
 import 'package:prosapp_web_app/providers/settings_provider.dart';
 import 'package:prosapp_web_app/providers/sidemenu_provider.dart';
+import 'package:prosapp_web_app/providers/theme_provider.dart';
 import 'package:prosapp_web_app/router/router.dart';
 import 'package:prosapp_web_app/services/local_storage.dart';
 import 'package:prosapp_web_app/services/navigation_service.dart';
@@ -26,15 +27,10 @@ import 'package:provider/provider.dart';
 
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
-
   await dotenv.load(fileName: ".env");
-
   await LocalStorage.configurePrefs();
-
   await initializeDateFormatting('es_ES', null);
-
   Flurorouter.configureRoutes();
-
   runApp(const AppState());
 }
 
@@ -48,6 +44,7 @@ class AppState extends StatelessWidget {
         ChangeNotifierProvider(lazy: false, create: (_) => AuthProvider()),
         ChangeNotifierProvider(lazy: false, create: (_) => SideMenuProvider()),
         ChangeNotifierProvider(lazy: false, create: (_) => ProfessionalProvider()),
+        ChangeNotifierProvider(lazy: false, create: (_) => ThemeProvider()),
         ChangeNotifierProvider(create: (_) => SettingsProvider()),
         ChangeNotifierProvider(create: (_) => ProfileFormProvider()),
         ChangeNotifierProvider(create: (_) => ProfessionalFormProvider()),
@@ -70,6 +67,8 @@ class MyApp extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final themeProvider = Provider.of<ThemeProvider>(context);
+
     return MaterialApp(
       debugShowCheckedModeBanner: false,
       title: 'ProsApp',
@@ -77,25 +76,46 @@ class MyApp extends StatelessWidget {
       onGenerateRoute: Flurorouter.router.generator,
       navigatorKey: NavigationService.navigatorKey,
       scaffoldMessengerKey: NotificationsService.messengerKey,
+      themeMode: themeProvider.mode,
+      theme: _buildLight(),
+      darkTheme: _buildDark(),
       builder: (_, child) {
         final authProvider = Provider.of<AuthProvider>(context);
-
-        if (authProvider.authStatus == AuthStatus.checking) {
-          return const SplashLayout();
-        }
-
-        if (authProvider.authStatus == AuthStatus.authenticated) {
-          return DashboardLayout(child: child!);
-        } else {
-          return AuthLayout(child: child!);
-        }
+        if (authProvider.authStatus == AuthStatus.checking) return const SplashLayout();
+        if (authProvider.authStatus == AuthStatus.authenticated) return DashboardLayout(child: child!);
+        return AuthLayout(child: child!);
       },
-      theme: ThemeData.light().copyWith(
-        scrollbarTheme: const ScrollbarThemeData().copyWith(
-          thumbColor: WidgetStateProperty.all(
-            Colors.grey.withOpacity(0.5),
-          ),
-        ),
+    );
+  }
+
+  ThemeData _buildLight() {
+    return ThemeData.light().copyWith(
+      colorScheme: ColorScheme.fromSeed(seedColor: const Color(0xFF42A4EF)),
+      scaffoldBackgroundColor: const Color(0xFFF4F6FA),
+      cardColor: Colors.white,
+      scrollbarTheme: const ScrollbarThemeData().copyWith(
+        thumbColor: WidgetStateProperty.all(Colors.grey.withOpacity(0.5)),
+      ),
+    );
+  }
+
+  ThemeData _buildDark() {
+    return ThemeData.dark().copyWith(
+      colorScheme: ColorScheme.fromSeed(
+        seedColor: const Color(0xFF42A4EF),
+        brightness: Brightness.dark,
+      ),
+      scaffoldBackgroundColor: const Color(0xFF0F172A),
+      cardColor: const Color(0xFF1E293B),
+      dialogBackgroundColor: const Color(0xFF1E293B),
+      appBarTheme: const AppBarTheme(backgroundColor: Color(0xFF1E293B)),
+      inputDecorationTheme: InputDecorationTheme(
+        filled: true,
+        fillColor: const Color(0xFF1E293B),
+        border: OutlineInputBorder(borderRadius: BorderRadius.circular(8)),
+      ),
+      scrollbarTheme: const ScrollbarThemeData().copyWith(
+        thumbColor: WidgetStateProperty.all(Colors.white24),
       ),
     );
   }