feat(ui): implement OAuth login flow and dashboard components

* Add OAuth login handling in app and UI components
* Create new components for login and dashboard pages
* Refactor sidebar and navigation structure
* Introduce types for access entries and status responses

ui/vite.config.ts

@@ -18,9 +18,6 @@ export default defineConfig({
       '/favicon.ico': backendTarget,
       '/mcp': backendTarget,
       '/files': backendTarget,
-      '/oauth-authorization-server': backendTarget,
-      '/authorize': backendTarget,
-      '/oauth': backendTarget,
       '/.well-known': backendTarget
     }
   },