feat: implement user authentication and admin management

- Add user management API endpoints for listing and creating users.
- Implement login and logout functionality with rate limiting.
- Create UI components for login form, logout button, and animated elements.
- Add session management with JWT and secure cookie handling.
- Seed initial admin user if no users exist.
- Introduce utility functions for password hashing and user authentication.
- Set up proxy middleware for route protection and security headers.
- Create a JSON file for user data storage.
- Add links configuration for external resources.

frontend/data/users.json

@@ -0,0 +1,10 @@
+[
+  {
+    "id": "00c94c52-f312-4152-a6ee-e3ce0b23b5f8",
+    "username": "admin",
+    "passwordHash": "827c32b2234fc18911ec8579ad6863df63b8cc3835b1f3a3f04016dfcd46f22e609cc3c99d5e09959ff8f2787f4169206ad5a9ca83beec2e70c14f8cca110cc8",
+    "salt": "c2030b38b34b2810f715453350100729",
+    "role": "admin",
+    "createdAt": "2026-05-12T12:46:52.082Z"
+  }
+]