use custom drift with isolate fixes

mobile/ios/Runner/Background/BackgroundWorker.swift

@@ -133,9 +133,9 @@ class BackgroundWorker: BackgroundWorkerBgHostApi {
       self.complete(success: false)
     }
 
-    // Fallback safety mechanism: ensure completion is called within 2 seconds
+    // Fallback safety mechanism: ensure completion is called within 5 seconds
     // This prevents the background task from hanging indefinitely if Flutter doesn't respond
-    Timer.scheduledTimer(withTimeInterval: 2, repeats: false) { _ in
+    Timer.scheduledTimer(withTimeInterval: 5, repeats: false) { _ in
       self.complete(success: false)
     }
   }

mobile/ios/Runner/Background/BackgroundWorkerApiImpl.swift

@@ -110,8 +110,8 @@ class BackgroundWorkerApiImpl: BackgroundWorkerFgHostApi {
       }
       isSuccess = false
       
-      // Schedule a timer to signal the semaphore after 2 seconds
-      Timer.scheduledTimer(withTimeInterval: 2, repeats: false) { _ in
+      // Schedule a timer to signal the semaphore after 5 seconds
+      Timer.scheduledTimer(withTimeInterval: 5, repeats: false) { _ in
         semaphore.signal()
       }
     }

mobile/lib/domain/services/background_worker.service.dart

@@ -61,8 +61,11 @@ class BackgroundWorkerFgService {
 
 class BackgroundWorkerBgService extends BackgroundWorkerFlutterApi {
   ProviderContainer? _ref;
+  // ignore: unused_field
   final Isar _isar;
+  // ignore: unused_field
   final Drift _drift;
+  // ignore: unused_field
   final DriftLogger _driftLogger;
   final BackgroundWorkerBgHostApi _backgroundHostApi;
   final CancellationToken _cancellationToken = CancellationToken();
@@ -79,7 +82,14 @@ class BackgroundWorkerBgService extends BackgroundWorkerFlutterApi {
       overrides: [
         dbProvider.overrideWithValue(isar),
         isarProvider.overrideWithValue(isar),
-        driftProvider.overrideWith(driftOverride(drift)),
+        // IMPORTANT: Do NOT use driftOverride here because it registers an onDispose
+        // callback that closes the database. Since the databases use shareAcrossIsolates: true,
+        // closing them from the background isolate will hang indefinitely.
+        // Instead, provide the drift instance directly without the dispose callback.
+        driftProvider.overrideWith((ref) {
+          ref.keepAlive();
+          return drift;
+        }),
       ],
     );
     BackgroundWorkerFlutterApi.setUp(this);
@@ -184,31 +194,38 @@ class BackgroundWorkerBgService extends BackgroundWorkerFlutterApi {
 
     try {
       _isCleanedUp = true;
+      _logger.info("Cleaning up background worker");
+
       final backgroundSyncManager = _ref?.read(backgroundSyncProvider);
       final nativeSyncApi = _ref?.read(nativeSyncApiProvider);
+
+      _cancellationToken.cancel();
+      await backgroundSyncManager?.cancel();
+      await nativeSyncApi?.cancelHashing();
+
+      // Dispose ref to release all providers
+      // Note: We use a custom drift provider override (see constructor) that does NOT
+      // close the database on dispose, so this is safe and won't hang
       _ref?.dispose();
       _ref = null;
 
-      _cancellationToken.cancel();
-      _logger.info("Cleaning up background worker");
-      final cleanupFutures = [
-        nativeSyncApi?.cancelHashing(),
-        workerManagerPatch.dispose().catchError((_) async {
-          // Discard any errors on the dispose call
-          return;
-        }),
-        LogService.I.dispose(),
-        Store.dispose(),
-        _drift.close(),
-        _driftLogger.close(),
-        backgroundSyncManager?.cancel(),
-      ];
+      try {
+        await workerManagerPatch.dispose();
+      } catch (_) {}
 
-      if (_isar.isOpen) {
-        cleanupFutures.add(_isar.close());
+      try {
+        await LogService.I.dispose();
+      } catch (error) {
+        _logger.warning("Failed to dispose LogService: $error");
       }
-      await Future.wait(cleanupFutures.nonNulls);
-      _logger.info("Background worker resources cleaned up");
+
+      try {
+        await Store.dispose();
+      } catch (error) {
+        _logger.warning("Failed to dispose Store: $error");
+      }
+
+      _logger.info("Background worker resources cleaned up successfully");
     } catch (error, stack) {
       dPrint(() => 'Failed to cleanup background worker: $error with stack: $stack');
     }

mobile/pubspec.lock

@@ -452,10 +452,11 @@ packages:
   drift:
     dependency: "direct main"
     description:
-      name: drift
-      sha256: "14a61af39d4584faf1d73b5b35e4b758a43008cf4c0fdb0576ec8e7032c0d9a5"
-      url: "https://pub.dev"
-    source: hosted
+      path: drift
+      ref: e7c909f0483b84510a9a60da8b020adc82ff16a3
+      resolved-ref: e7c909f0483b84510a9a60da8b020adc82ff16a3
+      url: "https://github.com/shenlong-tanwen/drift"
+    source: git
     version: "2.26.0"
   drift_dev:
     dependency: "direct dev"

mobile/pubspec.yaml

@@ -113,6 +113,13 @@ dev_dependencies:
   riverpod_generator: ^2.6.1
   riverpod_lint: ^2.6.1
 
+dependency_overrides:
+  drift:
+    git:
+      url: https://github.com/shenlong-tanwen/drift
+      ref: 'e7c909f0483b84510a9a60da8b020adc82ff16a3'
+      path: drift/
+
 flutter:
   uses-material-design: true
   assets: