Disable AI Scribe if on mobile

lib/features/composer/presentation/mixin/ai_scribe_in_composer_mixin.dart

@@ -23,6 +23,8 @@ mixin AIScribeInComposerMixin {
   AccountId? get accountId;
 
   bool get isAIScribeAvailable {
+    if (!PlatformInfo.isWeb) return false;
+
     final currentSession = session;
     final currentAccountId = accountId;
 

lib/features/mailbox_dashboard/presentation/controller/mailbox_dashboard_controller.dart

@@ -827,11 +827,15 @@ class MailboxDashBoardController extends ReloadableController
 
   void injectAIScribeBindings(Session? session, AccountId? accountId) {
     try {
+      if (!PlatformInfo.isWeb) return;
+
       if (session == null || accountId == null) return;
 
       final aiCapability = session.getAICapability(accountId);
       final scribeEndpoint = aiCapability?.scribeEndpoint;
 
+      if (scribeEndpoint == null || scribeEndpoint.isEmpty) return;
+
       // Delete existing AI bindings if they exist
       if (Get.isRegistered<AIDataSourceImpl>()) {
         Get.delete<AIDataSourceImpl>(force: true);