fix: cannot redirect to project page for the first time (#155)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

- **Refactor**
- Improved chat session navigation for smoother transitions and a more
integrated user experience.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: NarwhalChen

frontend/src/components/sidebar.tsx

@@ -20,6 +20,7 @@ import {
   SidebarFooter,
 } from './ui/sidebar';
 import { ProjectContext } from './chat/code-engine/project-context';
+import { useRouter } from 'next/navigation';
 
 interface SidebarProps {
   setIsModalOpen: (value: boolean) => void;