fix(server): wrap read-modify-write apis with distributed lock (#6142)

packages/backend/server/src/core/user/service.ts

@@ -54,7 +54,7 @@ export class UserService {
 
     return this.createUser({
       email,
-      name: 'Unnamed',
+      name: email.split('@')[0],
       ...data,
     });
   }