feat: refactor frontend routing and authentication

- Changed root div ID from 'root' to 'app' in index.html.
- Updated package.json to include new dependencies for routing and state management.
- Removed App component and replaced it with a router setup in main.tsx.
- Added route definitions for login, about, and index pages.
- Implemented authentication logic using Zustand for state management.
- Created API client with Axios for handling requests and token management.
- Added CORS support in the backend API.
- Updated schema for login requests to use camelCase.

.vscode/settings.json

@@ -0,0 +1,11 @@
+{
+  "files.readonlyInclude": {
+    "**/routeTree.gen.ts": true
+  },
+  "files.watcherExclude": {
+    "**/routeTree.gen.ts": true
+  },
+  "search.exclude": {
+    "**/routeTree.gen.ts": true
+  }
+}