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])

lib/core/database/database.g.dart

@@ -1246,6 +1246,7 @@ abstract class _$AppDatabase extends GeneratedDatabase {
   late final RoomsDao roomsDao = RoomsDao(this as AppDatabase);
   late final TasksDao tasksDao = TasksDao(this as AppDatabase);
   late final DailyPlanDao dailyPlanDao = DailyPlanDao(this as AppDatabase);
+  late final CalendarDao calendarDao = CalendarDao(this as AppDatabase);
   @override
   Iterable<TableInfo<Table, Object?>> get allTables =>
       allSchemaEntities.whereType<TableInfo<Table, Object?>>();

lib/features/home/data/calendar_dao.dart

@@ -0,0 +1,77 @@
+import 'package:drift/drift.dart';
+
+import '../../../core/database/database.dart';
+import '../domain/daily_plan_models.dart';
+
+part 'calendar_dao.g.dart';
+
+/// DAO for calendar-based task queries.
+///
+/// Provides date-parameterized queries to answer:
+/// - "What tasks are due on date X?"
+/// - "What tasks are overdue relative to today?"
+@DriftAccessor(tables: [Tasks, Rooms, TaskCompletions])
+class CalendarDao extends DatabaseAccessor<AppDatabase>
+    with _$CalendarDaoMixin {
+  CalendarDao(super.attachedDatabase);
+
+  /// Watch tasks whose [nextDueDate] falls on the given calendar day.
+  ///
+  /// Returns tasks sorted alphabetically by name.
+  /// Does NOT include overdue carry-over — only tasks originally due on [date].
+  Stream<List<TaskWithRoom>> watchTasksForDate(DateTime date) {
+    final startOfDay = DateTime(date.year, date.month, date.day);
+    final endOfDay = startOfDay.add(const Duration(days: 1));
+
+    final query = select(tasks).join([
+      innerJoin(rooms, rooms.id.equalsExp(tasks.roomId)),
+    ]);
+    query.where(
+      tasks.nextDueDate.isBiggerOrEqualValue(startOfDay) &
+          tasks.nextDueDate.isSmallerThanValue(endOfDay),
+    );
+    query.orderBy([OrderingTerm.asc(tasks.name)]);
+
+    return query.watch().map((rows) {
+      return rows.map((row) {
+        final task = row.readTable(tasks);
+        final room = row.readTable(rooms);
+        return TaskWithRoom(
+          task: task,
+          roomName: room.name,
+          roomId: room.id,
+        );
+      }).toList();
+    });
+  }
+
+  /// Watch tasks whose [nextDueDate] is strictly before [referenceDate].
+  ///
+  /// Returns tasks sorted by [nextDueDate] ascending (oldest first).
+  /// Does NOT include tasks due on [referenceDate] itself.
+  Stream<List<TaskWithRoom>> watchOverdueTasks(DateTime referenceDate) {
+    final startOfReferenceDay = DateTime(
+      referenceDate.year,
+      referenceDate.month,
+      referenceDate.day,
+    );
+
+    final query = select(tasks).join([
+      innerJoin(rooms, rooms.id.equalsExp(tasks.roomId)),
+    ]);
+    query.where(tasks.nextDueDate.isSmallerThanValue(startOfReferenceDay));
+    query.orderBy([OrderingTerm.asc(tasks.nextDueDate)]);
+
+    return query.watch().map((rows) {
+      return rows.map((row) {
+        final task = row.readTable(tasks);
+        final room = row.readTable(rooms);
+        return TaskWithRoom(
+          task: task,
+          roomName: room.name,
+          roomId: room.id,
+        );
+      }).toList();
+    });
+  }
+}

lib/features/home/data/calendar_dao.g.dart

@@ -0,0 +1,25 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'calendar_dao.dart';
+
+// ignore_for_file: type=lint
+mixin _$CalendarDaoMixin on DatabaseAccessor<AppDatabase> {
+  $RoomsTable get rooms => attachedDatabase.rooms;
+  $TasksTable get tasks => attachedDatabase.tasks;
+  $TaskCompletionsTable get taskCompletions => attachedDatabase.taskCompletions;
+  CalendarDaoManager get managers => CalendarDaoManager(this);
+}
+
+class CalendarDaoManager {
+  final _$CalendarDaoMixin _db;
+  CalendarDaoManager(this._db);
+  $$RoomsTableTableManager get rooms =>
+      $$RoomsTableTableManager(_db.attachedDatabase, _db.rooms);
+  $$TasksTableTableManager get tasks =>
+      $$TasksTableTableManager(_db.attachedDatabase, _db.tasks);
+  $$TaskCompletionsTableTableManager get taskCompletions =>
+      $$TaskCompletionsTableTableManager(
+        _db.attachedDatabase,
+        _db.taskCompletions,
+      );
+}