feat: Enhance messaging read receipts and auto-read, fix auth 401 error suppression during logout, and refine agent profile expertise

lib/core/network/api_client.dart

@@ -14,6 +14,9 @@ class ApiClient {
   bool _isRefreshing = false;
   final List<_QueuedRequest> _failedQueue = [];
 
+  // Suppress 401 errors during logout to prevent SnackBar flashing
+  static bool suppressAuthErrors = false;
+
   // Callback to notify app of forced logout
   static void Function()? onForceLogout;
 
@@ -60,6 +63,12 @@ class ApiClient {
       onError: (error, handler) async {
         // Handle 401 — attempt token refresh
         if (error.response?.statusCode == 401) {
+          // During logout, silently reject 401s without showing errors
+          if (suppressAuthErrors) {
+            handler.reject(error);
+            return;
+          }
+
           final requestUrl = error.requestOptions.path;
 
           // Don't try to refresh if this was the refresh request itself