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.

libertas-frontend/src/hooks/use-auth-storage.ts

@@ -0,0 +1,29 @@
+import { create } from 'zustand'
+import { createJSONStorage, persist } from 'zustand/middleware'
+import type { User } from "@/domain/types"
+
+type AuthState = {
+  token: string | null
+  user: User | null
+  setToken: (token: string, user: User) => void
+  clearToken: () => void
+}
+
+/**
+ * Global store for authentication state (token and user).
+ * Persisted to localStorage.
+ */
+export const useAuthStorage = create<AuthState>()(
+  persist(
+    (set) => ({
+      token: null,
+      user: null,
+      setToken: (token, user) => set({ token, user }),
+      clearToken: () => set({ token: null, user: null }),
+    }),
+    {
+      name: 'auth-storage',
+      storage: createJSONStorage(() => localStorage),
+    },
+  ),
+)