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/features/tasks/presentation/task_list_screen_test.dart

@@ -30,6 +30,7 @@ Task _makeTask({
     effortLevel: EffortLevel.medium,
     nextDueDate: nextDueDate,
     createdAt: DateTime(2026, 1, 1),
+    isActive: true,
   );
 }