Improve duplicate team member error message

ui/litellm-dashboard/src/components/networking.tsx

@@ -5,6 +5,7 @@ import { all_admin_roles } from "@/utils/roles";
 import { message } from "antd";
 import { TagNewRequest, TagUpdateRequest, TagDeleteRequest, TagInfoRequest, TagListResponse, TagInfoResponse } from "./tag_management/types";
 import { Team } from "./key_team_helpers/key_list";
+import { UiError } from "@/utils/errorUtils";
 
 const isLocal = process.env.NODE_ENV === "development";
 export const proxyBaseUrl = isLocal ? "http://localhost:4000" : null;
@@ -3263,7 +3264,10 @@ export const teamMemberAddCall = async (
       const errorData = await response.text();
       handleError(errorData);
       console.error("Error response from the server:", errorData);
-      throw new Error("Network response was not ok");
+      if (errorData.includes('already in team')) {
+        throw new UiError("User is already a member of this team") 
+      }
+      throw new Error("Failed to add team member");
     }
 
     const data = await response.json();

ui/litellm-dashboard/src/components/team/team_info.tsx

@@ -33,6 +33,7 @@ import MemberModal from "./edit_membership";
 import UserSearchModal from "@/components/common_components/user_search_modal";
 import { getModelDisplayName } from "../key_team_helpers/fetch_available_models_team_key";
 import { isAdminRole } from "@/utils/roles";
+import { UiError } from "@/utils/errorUtils";
 
 export interface TeamData {
   team_id: string;
@@ -131,7 +132,12 @@ const TeamInfoView: React.FC<TeamInfoProps> = ({
       form.resetFields();
       fetchTeamInfo();
     } catch (error) {
-      message.error("Failed to add team member");
+      if (error instanceof UiError) {
+        message.error(error.message)
+      } else {
+        message.error("Failed to add team member");
+      }
+
       console.error("Error adding team member:", error);
     }
   };

ui/litellm-dashboard/src/utils/errorUtils.ts

@@ -0,0 +1,6 @@
+export class UiError extends Error {
+  constructor(message: string) {
+    super(message);
+    Object.setPrototypeOf(this, UiError.prototype)
+  }
+}