feat(ui): écran Création/édition de programme

Ajoute l'écran de programme (presentation/program_screen.dart) et un
écran d'accueil (presentation/home_screen.dart) pour la navigation,
avec les ajustements application/domaine/repositories nécessaires.
flutter analyze propre, 11/11 tests verts, build APK debug validé.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

lib/application/app_bootstrap.dart

@@ -6,17 +6,20 @@ final class AppBootstrap {
     required this.database,
     required this.exerciseUseCases,
     required this.mediaUseCases,
+    required this.programUseCases,
   });
 
   final AppDatabase database;
   final ExerciseUseCases exerciseUseCases;
   final MediaUseCases mediaUseCases;
+  final ProgramUseCases programUseCases;
 
   static Future<AppBootstrap> create() async {
     final database = AppDatabase.open();
     await database.customSelect('SELECT 1').get();
     final exerciseRepository = DriftExerciseRepository(database);
     final mediaRepository = DriftMediaAssetRepository(database);
+    final programRepository = DriftProgramRepository(database);
     final ids = LocalIdGenerator();
     const clock = SystemClock();
     const originDeviceId = 'local-device';
@@ -37,6 +40,13 @@ final class AppBootstrap {
         ids: ids,
         originDeviceId: originDeviceId,
       ),
+      programUseCases: ProgramUseCases(
+        programRepository: programRepository,
+        exerciseRepository: exerciseRepository,
+        clock: clock,
+        ids: ids,
+        originDeviceId: originDeviceId,
+      ),
     );
   }