🐛 fix(web/layout): explicitly import headerbar/index.jsx to resolve Linux build failure

The Linux/Vite build failed with:
“Could not resolve "./headerbar" from "src/components/layout/PageLayout.jsx"”

On Linux and with stricter ESM/rollup resolution, directory index files (index.jsx)
may not be auto-resolved reliably. Explicitly importing the index file ensures
cross-platform stability.

Changes:
- Update PageLayout import from "./headerbar" to "./headerbar/index.jsx"

Impact:
- Fixes build on Linux
- No runtime behavior changes

Verification:
- Linter passes for web/src/components/layout/PageLayout.jsx

Notes:
- Prefer explicit index file imports (and extensions) to avoid platform differences.

web/src/components/layout/PageLayout.jsx

@@ -17,7 +17,7 @@ along with this program. If not, see <https://www.gnu.org/licenses/>.
 For commercial licensing, please contact support@quantumnous.com
 */
 
-import HeaderBar from './headerbar';
+import HeaderBar from './headerbar/index.jsx';
 import { Layout } from '@douyinfe/semi-ui';
 import SiderBar from './SiderBar';
 import App from '../../App';