feat(08-01): add isActive filters to CalendarDao, DailyPlanDao, RoomsDao

- CalendarDao: filter all 6 task queries (watchTasksForDate,
  watchTasksForDateInRoom, watchOverdueTasks, watchOverdueTasksInRoom,
  getTaskCount, getTaskCountInRoom) by isActive=true
- DailyPlanDao: filter all 3 queries (watchAllTasksWithRoomName,
  getOverdueAndTodayTaskCount, getOverdueTaskCount) by isActive=true
- RoomsDao: filter watchRoomWithStats task query by isActive=true
- Update migration test: add schema_v3.dart, test v1->v3 and v2->v3 paths
- Update database_test schemaVersion assertion to expect 3
- Fix test helpers in home_screen_test and task_list_screen_test to pass isActive=true

test/core/database/database_test.dart

@@ -18,8 +18,8 @@ void main() {
       expect(db, isNotNull);
     });
 
-    test('has schemaVersion 2', () {
-      expect(db.schemaVersion, equals(2));
+    test('has schemaVersion 3', () {
+      expect(db.schemaVersion, equals(3));
     });
 
     test('can be closed without error', () async {