feat(U2): sync local drafts with IMAP Drafts folder

- Add imapServerId column (schema v24) to Drafts table; guard migration
  with from>=4 since createTable already uses latest schema
- Extend SavedDraft model and DraftRepository interface with syncDrafts()
- Implement syncDrafts in DraftRepositoryImpl: create/select Drafts
  folder, upload local-only drafts via APPEND, import server drafts not
  tracked locally
- Wire AccountRepository and ImapConnectFn into DraftRepositoryImpl via
  draftRepositoryProvider
- Call syncDrafts from AccountSyncManager._AccountSync._sync() so each
  IMAP sync cycle also syncs the Drafts folder
- Add syncDrafts stub to FakeDraftRepository; update unit test
  constructor calls with _StubAccounts

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

android/app/build.gradle.kts

@@ -35,7 +35,7 @@ android {
         applicationId = "de.sharedinbox.mua"
         // You can update the following values to match your application needs.
         // For more information, see: https://flutter.dev/to/review-gradle-config.
-        minSdk = 23
+        minSdk = flutter.minSdkVersion
         targetSdk = flutter.targetSdkVersion
         versionCode = flutter.versionCode
         versionName = flutter.versionName

android/app/src/main/AndroidManifest.xml

@@ -1,8 +1,5 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
     <uses-permission android:name="android.permission.INTERNET"/>
-    <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
-    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
-    <uses-permission android:name="android.permission.WAKE_LOCK"/>
     <application
         android:label="sharedinbox"
         android:name="${applicationName}"

lib/core/services/notification_service.dart

@@ -1,38 +0,0 @@
-import 'dart:io';
-
-import 'package:flutter_local_notifications/flutter_local_notifications.dart';
-
-const _kChannelId = 'new_mail';
-const _kChannelName = 'New mail';
-
-final _plugin = FlutterLocalNotificationsPlugin();
-
-Future<void> initNotifications() async {
-  const android = AndroidInitializationSettings('@mipmap/ic_launcher');
-  await _plugin.initialize(
-    const InitializationSettings(android: android),
-    onDidReceiveNotificationResponse: (_) {},
-  );
-  await _plugin
-      .resolvePlatformSpecificImplementation<
-          AndroidFlutterLocalNotificationsPlugin>()
-      ?.requestNotificationsPermission();
-}
-
-Future<void> showNewMailNotification(String accountEmail) async {
-  if (!Platform.isAndroid) return;
-  await _plugin.show(
-    accountEmail.hashCode & 0x7FFFFFFF,
-    'New mail',
-    accountEmail,
-    const NotificationDetails(
-      android: AndroidNotificationDetails(
-        _kChannelId,
-        _kChannelName,
-        channelDescription: 'Notifications for new incoming mail',
-        importance: Importance.high,
-        priority: Priority.high,
-      ),
-    ),
-  );
-}

lib/core/sync/account_sync_manager.dart

@@ -12,8 +12,6 @@ import 'package:sharedinbox/core/utils/logger.dart';
 import 'package:sharedinbox/data/imap/imap_client_factory.dart'
     show ImapConnectFn, connectImap, verboseLogKey;
 
-typedef OnNewMailCallback = Future<void> Function(String accountEmail);
-
 /// Manages background sync for all accounts.
 ///
 /// IMAP accounts get an IDLE-based sync loop (_AccountSync).
@@ -26,11 +24,9 @@ class AccountSyncManager {
     ImapConnectFn imapConnect = connectImap,
     SyncLogRepository syncLog = const NoOpSyncLogRepository(),
     DraftRepository? drafts,
-    OnNewMailCallback? onNewMail,
   })  : _imapConnect = imapConnect,
         _syncLog = syncLog,
-        _drafts = drafts,
-        _onNewMail = onNewMail;
+        _drafts = drafts;
 
   final AccountRepository _accounts;
   final MailboxRepository _mailboxes;
@@ -38,7 +34,6 @@ class AccountSyncManager {
   final ImapConnectFn _imapConnect;
   final SyncLogRepository _syncLog;
   final DraftRepository? _drafts;
-  final OnNewMailCallback? _onNewMail;
 
   final Map<String, _SyncLoop> _active = {};
   StreamSubscription<List<Account>>? _accountsSub;
@@ -63,7 +58,6 @@ class AccountSyncManager {
               _imapConnect,
               _syncLog,
               _drafts,
-              _onNewMail,
             ),
           AccountType.jmap => _JmapAccountSync(
               account,
@@ -125,7 +119,6 @@ class AccountSyncManager {
           _imapConnect,
           _syncLog,
           _drafts,
-          _onNewMail,
         ),
       AccountType.jmap => _JmapAccountSync(
           account,
@@ -159,7 +152,6 @@ class _AccountSync implements _SyncLoop {
     this._imapConnect,
     this._syncLog,
     this._drafts,
-    this._onNewMail,
   );
 
   final Account account;
@@ -169,7 +161,6 @@ class _AccountSync implements _SyncLoop {
   final ImapConnectFn _imapConnect;
   final SyncLogRepository _syncLog;
   final DraftRepository? _drafts;
-  final OnNewMailCallback? _onNewMail;
 
   imap.ImapClient? _idleClient;
   bool _running = false;
@@ -344,7 +335,6 @@ class _AccountSync implements _SyncLoop {
       await client.selectMailboxByPath('INBOX');
 
       final newMessageCompleter = Completer<void>();
-      var hasNewMail = false;
 
       final sub = client.eventBus
           .on<imap.ImapEvent>()
@@ -352,11 +342,7 @@ class _AccountSync implements _SyncLoop {
             (e) =>
                 e is imap.ImapMessagesExistEvent || e is imap.ImapExpungeEvent,
           )
-          .listen((e) {
-        if (e is imap.ImapMessagesExistEvent &&
-            e.newMessagesExists > e.oldMessagesExists) {
-          hasNewMail = true;
-        }
+          .listen((_) {
         if (!newMessageCompleter.isCompleted) newMessageCompleter.complete();
       });
 
@@ -372,10 +358,6 @@ class _AccountSync implements _SyncLoop {
 
       await client.idleDone();
       await sub.cancel();
-
-      if (hasNewMail) {
-        unawaited(_onNewMail?.call(account.email));
-      }
     } finally {
       await client.logout();
       _idleClient = null;

lib/core/sync/background_sync.dart

@@ -1,123 +0,0 @@
-import 'dart:async';
-import 'dart:convert';
-import 'dart:io';
-
-import 'package:drift/drift.dart';
-import 'package:drift/native.dart';
-import 'package:enough_mail/enough_mail.dart' as imap;
-import 'package:path/path.dart' as p;
-import 'package:path_provider/path_provider.dart';
-
-import 'package:sharedinbox/core/models/account.dart' as model;
-import 'package:sharedinbox/core/repositories/account_repository.dart';
-import 'package:sharedinbox/core/services/notification_service.dart';
-import 'package:sharedinbox/data/db/database.dart';
-import 'package:sharedinbox/data/imap/imap_client_factory.dart';
-import 'package:sharedinbox/data/repositories/account_repository_impl.dart';
-import 'package:sharedinbox/data/storage/flutter_secure_storage_impl.dart';
-
-import 'package:workmanager/workmanager.dart';
-
-const _kTaskName = 'si_bg_sync';
-const _kResourceType = 'background_check';
-
-@pragma('vm:entry-point')
-void callbackDispatcher() {
-  Workmanager().executeTask((_, __) async {
-    try {
-      await _doBackgroundSync();
-    } catch (_) {}
-    return true;
-  });
-}
-
-Future<void> registerBackgroundSync() async {
-  await Workmanager().initialize(callbackDispatcher);
-  await Workmanager().registerPeriodicTask(
-    _kTaskName,
-    _kTaskName,
-    frequency: const Duration(minutes: 15),
-    constraints: Constraints(networkType: NetworkType.connected),
-    existingWorkPolicy: ExistingWorkPolicy.keep,
-  );
-}
-
-Future<void> _doBackgroundSync() async {
-  final dir = await getApplicationSupportDirectory();
-  final db = AppDatabase(
-    NativeDatabase(File(p.join(dir.path, 'sharedinbox.db'))),
-  );
-  try {
-    final accountRepo = AccountRepositoryImpl(
-      db,
-      const FlutterSecureStorageImpl(),
-    );
-    final accounts = await accountRepo.observeAccounts().first;
-    await initNotifications();
-    for (final account in accounts) {
-      if (account.type != model.AccountType.imap) continue;
-      await _checkAccount(db, accountRepo, account);
-    }
-  } finally {
-    await db.close();
-  }
-}
-
-Future<void> _checkAccount(
-  AppDatabase db,
-  AccountRepository accountRepo,
-  model.Account account,
-) async {
-  try {
-    final password = await accountRepo.getPassword(account.id);
-    final username =
-        account.username.isNotEmpty ? account.username : account.email;
-    final client = await connectImap(account, username, password);
-    try {
-      final status = await client.statusMailbox(
-        imap.Mailbox.virtual('INBOX', []),
-        [imap.StatusFlags.uidNext],
-      );
-      final currentUidNext = status.uidNext;
-
-      final stored = await (db.select(db.syncStates)
-            ..where(
-              (t) =>
-                  t.accountId.equals(account.id) &
-                  t.resourceType.equals(_kResourceType),
-            ))
-          .getSingleOrNull();
-      final lastUidNext = _parseUidNext(stored?.state);
-
-      await db.into(db.syncStates).insertOnConflictUpdate(
-            SyncStatesCompanion.insert(
-              accountId: account.id,
-              resourceType: _kResourceType,
-              state: jsonEncode({'uidNext': currentUidNext}),
-              syncedAt: DateTime.now(),
-            ),
-          );
-
-      if (lastUidNext != null &&
-          currentUidNext != null &&
-          currentUidNext > lastUidNext) {
-        await showNewMailNotification(account.email);
-      }
-    } finally {
-      await client.logout();
-    }
-  } catch (_) {}
-}
-
-int? _parseUidNext(String? state) {
-  if (state == null) return null;
-  try {
-    final decoded = jsonDecode(state);
-    if (decoded is Map<String, Object?>) {
-      return decoded['uidNext'] as int?;
-    }
-    return null;
-  } catch (_) {
-    return null;
-  }
-}

lib/di.dart

@@ -12,7 +12,6 @@ import 'package:sharedinbox/core/repositories/undo_repository.dart';
 import 'package:sharedinbox/core/services/account_discovery_service.dart';
 import 'package:sharedinbox/core/services/connection_test_service.dart';
 import 'package:sharedinbox/core/services/managesieve_probe_service.dart';
-import 'package:sharedinbox/core/services/notification_service.dart';
 import 'package:sharedinbox/core/services/undo_service.dart';
 import 'package:sharedinbox/core/storage/secure_storage.dart';
 import 'package:sharedinbox/core/sync/account_sync_manager.dart';
@@ -123,7 +122,6 @@ final syncManagerProvider = Provider<AccountSyncManager>((ref) {
     syncLog: ref.watch(syncLogRepositoryProvider),
     imapConnect: ref.watch(imapConnectProvider),
     drafts: ref.watch(draftRepositoryProvider),
-    onNewMail: showNewMailNotification,
   );
   ref.onDispose(manager.dispose);
   return manager;

lib/main.dart

@@ -1,11 +1,8 @@
 import 'dart:async';
-import 'dart:io';
 
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
-import 'package:sharedinbox/core/services/notification_service.dart';
-import 'package:sharedinbox/core/sync/background_sync.dart';
 import 'package:sharedinbox/data/db/database.dart';
 import 'package:sharedinbox/di.dart';
 import 'package:sharedinbox/ui/router.dart';
@@ -35,10 +32,6 @@ void main({List<Override> overrides = const []}) async {
         };
 
         await initDatabasePath();
-        if (Platform.isAndroid) {
-          await initNotifications();
-          await registerBackgroundSync();
-        }
         runApp(
           ProviderScope(overrides: overrides, child: const SharedInboxApp()),
         );

pubspec.yaml

@@ -45,10 +45,6 @@ dependencies:
   url_launcher: ^6.3.2
   flutter_markdown: ^0.7.7+1
 
-  # Background sync and local notifications
-  flutter_local_notifications: ^18.0.1
-  workmanager: ^0.5.2
-
 dev_dependencies:
   flutter_test:
     sdk: flutter

scripts/check_coverage.dart

@@ -52,7 +52,6 @@ const _excluded = {
   'lib/ui/widgets/try_connection_button.dart',
   'lib/ui/widgets/undo_shell.dart',
   'lib/core/sync/account_sync_manager.dart',
-  'lib/core/sync/background_sync.dart',
   'lib/core/sync/reliability_runner.dart',
   'lib/data/jmap/jmap_client.dart',
   'lib/data/jmap/sieve_repository.dart',