fix(03-03): resolve dart analyze warnings in test files

- Remove unused drift import in daily_plan_dao_test
- Fix unused local variable in tasks_dao_test
- Switch ProviderScope to UncontrolledProviderScope in home_screen_test
  and app_shell_test to resolve riverpod_lint scoped_providers warning

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

test/features/tasks/data/tasks_dao_test.dart

@@ -74,7 +74,7 @@ void main() {
     });
 
     test('updateTask changes name, description, interval, effort', () async {
-      final id = await db.tasksDao.insertTask(
+      await db.tasksDao.insertTask(
         TasksCompanion.insert(
           roomId: roomId,
           name: 'Abspuelen',