fix: handle network errors during login to prevent TypeError crash

The login method in EmbeddedChatApi.ts returned undefined when a
non-401 error occurred (e.g. network failure). This caused a
TypeError in useRCAuth.js when accessing res.error on the undefined
response, crashing the login flow silently.

Changes:
- EmbeddedChatApi.ts: return an error object for all caught errors
  instead of implicitly returning undefined
- useRCAuth.js: add a null guard on the login response as a safety
  net, showing a toast message if the response is missing

Fixes #1210

Author: mufeezhanif

packages/api/src/EmbeddedChatApi.ts

@@ -143,6 +143,7 @@ export default class EmbeddedChatApi {
         return { error: authErrorRes?.error };
       }
       console.error(error);
+      return { error: error instanceof Error ? error.message : 'unknown-error' };
     }
   }
 

packages/react/src/hooks/useRCAuth.js

@@ -25,6 +25,14 @@ export const useRCAuth = () => {
   const handleLogin = async (userOrEmail, password, code) => {
     try {
       const res = await RCInstance.login(userOrEmail, password, code);
+      if (!res) {
+        dispatchToastMessage({
+          type: 'error',
+          message:
+            'Unable to connect to server. Please check your connection and try again.',
+        });
+        return;
+      }
       if (res.error === 'Unauthorized' || res.error === 403) {
         dispatchToastMessage({
           type: 'error',