fix: use full API URL for OAuth login redirects

In Traefik deployment, API and web are on different domains.
Frontend was using relative paths (/auth/login) which resolved
to the web domain instead of the API domain.

- Update LoginRedirectPage to use VITE_API_BASE_URL for login link
- Update apiClient 401 interceptor to redirect to full API URL
- Ensures OAuth flow works correctly with separate domains

apps/web/src/api/client.ts

@@ -19,7 +19,7 @@ apiClient.interceptors.response.use(
   (error) => {
     const status = error?.response?.status;
     if (status === 401 && !shouldSkipAuthRedirect(window.location.pathname)) {
-      window.location.assign("/auth/login");
+      window.location.assign(`${BASE_URL}/auth/login`);
     }
     return Promise.reject(error);
   }