feat(05-01): implement CalendarDao with date-parameterized task queries

- CalendarDao.watchTasksForDate: returns tasks due on a specific calendar day, sorted by name
- CalendarDao.watchOverdueTasks: returns tasks due strictly before reference date, sorted by due date
- Registered CalendarDao in AppDatabase @DriftDatabase annotation
- Generated calendar_dao.g.dart and updated database.g.dart

lib/core/database/database.dart

@@ -2,6 +2,7 @@ import 'package:drift/drift.dart';
 import 'package:drift_flutter/drift_flutter.dart';
 import 'package:path_provider/path_provider.dart';
 
+import '../../features/home/data/calendar_dao.dart';
 import '../../features/home/data/daily_plan_dao.dart';
 import '../../features/rooms/data/rooms_dao.dart';
 import '../../features/tasks/data/tasks_dao.dart';
@@ -45,7 +46,7 @@ class TaskCompletions extends Table {
 
 @DriftDatabase(
   tables: [Rooms, Tasks, TaskCompletions],
-  daos: [RoomsDao, TasksDao, DailyPlanDao],
+  daos: [RoomsDao, TasksDao, DailyPlanDao, CalendarDao],
 )
 class AppDatabase extends _$AppDatabase {
   AppDatabase([QueryExecutor? executor])