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

lib/features/home/data/daily_plan_dao.dart

@@ -10,13 +10,14 @@ class DailyPlanDao extends DatabaseAccessor<AppDatabase>
     with _$DailyPlanDaoMixin {
   DailyPlanDao(super.attachedDatabase);
 
-  /// Watch all tasks joined with room name, sorted by nextDueDate ascending.
-  /// Includes ALL tasks (overdue, today, future) -- filtering is done in the
-  /// provider layer to avoid multiple queries.
+  /// Watch all active tasks joined with room name, sorted by nextDueDate ascending.
+  /// Includes overdue, today, and future tasks -- filtering is done in the
+  /// provider layer to avoid multiple queries. Excludes soft-deleted tasks.
   Stream<List<TaskWithRoom>> watchAllTasksWithRoomName() {
     final query = select(tasks).join([
       innerJoin(rooms, rooms.id.equalsExp(tasks.roomId)),
     ]);
+    query.where(tasks.isActive.equals(true));
     query.orderBy([OrderingTerm.asc(tasks.nextDueDate)]);
 
     return query.watch().map((rows) {
@@ -32,24 +33,30 @@ class DailyPlanDao extends DatabaseAccessor<AppDatabase>
     });
   }
 
-  /// One-shot count of overdue + today tasks (for notification body).
+  /// One-shot count of overdue + today active tasks (for notification body).
   Future<int> getOverdueAndTodayTaskCount({DateTime? today}) async {
     final now = today ?? DateTime.now();
     final endOfToday = DateTime(now.year, now.month, now.day + 1);
     final result = await (selectOnly(tasks)
           ..addColumns([tasks.id.count()])
-          ..where(tasks.nextDueDate.isSmallerThanValue(endOfToday)))
+          ..where(
+            tasks.nextDueDate.isSmallerThanValue(endOfToday) &
+                tasks.isActive.equals(true),
+          ))
         .getSingle();
     return result.read(tasks.id.count()) ?? 0;
   }
 
-  /// One-shot count of overdue tasks only (for notification body split).
+  /// One-shot count of overdue active tasks only (for notification body split).
   Future<int> getOverdueTaskCount({DateTime? today}) async {
     final now = today ?? DateTime.now();
     final startOfToday = DateTime(now.year, now.month, now.day);
     final result = await (selectOnly(tasks)
           ..addColumns([tasks.id.count()])
-          ..where(tasks.nextDueDate.isSmallerThanValue(startOfToday)))
+          ..where(
+            tasks.nextDueDate.isSmallerThanValue(startOfToday) &
+                tasks.isActive.equals(true),
+          ))
         .getSingle();
     return result.read(tasks.id.count()) ?? 0;
   }