improved performance and battery usage on older devices

lib/state/app/modules/settings/bloc/settings_cubit.dart

@@ -1,6 +1,7 @@
 import 'dart:async';
 import 'dart:developer';
 
+import 'package:collection/collection.dart';
 import 'package:hydrated_bloc/hydrated_bloc.dart';
 
 import '../../../../../storage/settings.dart';
@@ -10,6 +11,8 @@ import '../../../../../view/pages/settings/data/default_settings.dart';
 class SettingsCubit extends HydratedCubit<Settings> {
   static const _debounceTag = 'settings_persist';
   bool _emitScheduled = false;
+  Map<String, dynamic>? _lastEmittedJson;
+  Timer? _silentSave;
 
   SettingsCubit() : super(DefaultSettings.get());
 
@@ -34,21 +37,53 @@ class SettingsCubit extends HydratedCubit<Settings> {
     return state;
   }
 
+  /// Persists in-place mutations without notifying listeners. For high-frequency
+  /// writes nobody renders live (chat drafts per keystroke): a regular write
+  /// would rebuild the app root and every settings watcher on each change.
+  void saveSilently() {
+    _silentSave?.cancel();
+    _silentSave = Timer(const Duration(milliseconds: 800), flushSilentSave);
+  }
+
+  /// Writes a pending [saveSilently] right away (e.g. when the app pauses).
+  void flushSilentSave() {
+    if (_silentSave == null) return;
+    _silentSave!.cancel();
+    _silentSave = null;
+    HydratedBloc.storage.write(storageToken, state.toJson());
+  }
+
   void _emitFreshInstance() {
     try {
-      emit(Settings.fromJson(state.toJson()));
+      final json = state.toJson();
+      // The debounced emit usually follows the microtask emit with identical
+      // content; skip it instead of rebuilding every listener a second time.
+      if (const DeepCollectionEquality().equals(json, _lastEmittedJson)) {
+        return;
+      }
+      _lastEmittedJson = json;
+      emit(Settings.fromJson(json));
     } catch (e) {
       log('Failed to refresh settings state: $e');
     }
   }
 
   Future<void> reset() async {
+    _silentSave?.cancel();
+    _silentSave = null;
+    _lastEmittedJson = null;
     emit(DefaultSettings.get());
   }
 
   // Modules missing from a stale persisted moduleOrder are handled at read
   // time by AppModule.effectiveModuleOrder (inserted at their default
   // position) — no healing on hydration needed.
+  @override
+  Future<void> close() {
+    flushSilentSave();
+    return super.close();
+  }
+
   @override
   Settings fromJson(Map<String, dynamic> json) {
     try {