fix(ui): Improve token refresh error handling

- Return false instead of throwing error when no refresh token exists
    - Prevent logout on refresh error, just log warning and return false
    - Avoid throwing errors that could break the application flow

ui/vbase.js

@@ -181,7 +181,7 @@ class VBase {
   }
 
   async refresh() {
-    if (!this.refreshToken) throw new Error("No refresh token");
+    if (!this.refreshToken) return false;
     try {
       const data = await this.request('POST', '/api/auth/refresh', { refresh_token: this.refreshToken });
       if (data.access_token) {
@@ -191,8 +191,8 @@ class VBase {
       }
       return false;
     } catch (e) {
-      this.logout();
-      throw e;
+      console.warn(e)
+      return false
     }
   }