Initialise l'app Flutter mobile : BDD Drift, onboarding sans compte et tableau de bord.

Phase 1 du MVP : schéma SQLite porté depuis le prototype web, seed des règles/récompenses, flux d'onboarding en 4 étapes et écran d'accueil minimal.

Co-authored-by: Cursor <cursoragent@cursor.com>

mobile/lib/providers/database_provider.dart

@@ -0,0 +1,24 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import '../data/database/app_database.dart';
+import '../data/repositories/onboarding_repository.dart';
+
+final databaseProvider = Provider<AppDatabase>((ref) {
+  final db = AppDatabase();
+  ref.onDispose(db.close);
+  return db;
+});
+
+final onboardingRepositoryProvider = Provider<OnboardingRepository>((ref) {
+  return OnboardingRepository(ref.watch(databaseProvider));
+});
+
+final onboardingCompleteProvider = FutureProvider<bool>((ref) async {
+  final repo = ref.watch(onboardingRepositoryProvider);
+  return repo.isComplete();
+});
+
+final childrenProvider = FutureProvider<List<Enfant>>((ref) async {
+  final db = ref.watch(databaseProvider);
+  return db.listChildren();
+});