docs(phase-2): complete context and implementation planning

- Documented comprehensive plan for Phase 2: Rooms and Tasks
- Includes feature scope, requirements, implementation decisions, UI/UX specifics, and scheduling logic
- Updated schema: added Room and Task tables with CRUD and recurrence support
- Added implementation details for room/task templates, cleanliness indicators, and overdue task handling
- Generated Drift schemas for database versioning (v1 → v2) with test coverage

lib/main.dart

@@ -10,8 +10,8 @@ import 'package:household_keeper/core/notifications/notification_service.dart';
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
   tz.initializeTimeZones();
-  final timeZoneName = await FlutterTimezone.getLocalTimezone();
-  tz.setLocalLocation(tz.getLocation(timeZoneName));
+  final timeZone = await FlutterTimezone.getLocalTimezone();
+  tz.setLocalLocation(tz.getLocation(timeZone.identifier));
   await NotificationService().initialize();
   runApp(const ProviderScope(child: App()));
 }