chore: trim redundant comments

lib/providers/download_queue_provider.dart

@@ -6676,9 +6676,7 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
       }
     }
 
-    // iOS has no foreground service; request a background execution window so
-    // an in-flight download can keep running for a short time after the app is
-    // backgrounded instead of being suspended immediately.
+    // iOS: request a background execution window (no foreground service).
     if (Platform.isIOS && _totalQueuedAtStart > 0) {
       await PlatformBridge.beginBackgroundDownloadTask();
     }

lib/providers/store_provider.dart

@@ -206,10 +206,7 @@ class StoreState {
 }
 
 class StoreNotifier extends Notifier<StoreState> {
-  /// Serializes extension install/upgrade operations. Running two of these at
-  /// once (e.g. updating two extensions simultaneously) races the native
-  /// extension manager's goja VM teardown/reload and can hard-crash the app, so
-  /// they must run strictly one at a time.
+  /// Serializes install/upgrade so two never race the native VM teardown/reload.
   Future<void> _mutationChain = Future<void>.value();
 
   Future<T> _runSerialized<T>(Future<T> Function() action) {