feat: add authentication modal component and user authentication logic

- Implemented AuthModal.vue for user login and registration with form handling.
- Created useAuth composable for managing user state and authentication requests.
- Added admin route middleware to protect admin routes.
- Developed admin login page with authentication checks.
- Implemented API endpoints for user management (login, logout, fetch user, register).
- Created database migrations for users table and updated movies table.
- Added utility functions for password hashing and JWT token management.

app/middleware/admin.global.ts

@@ -0,0 +1,16 @@
+export default defineNuxtRouteMiddleware(async (to) => {
+  if (!to.path.startsWith('/admin')) return
+  if (to.path === '/admin/login') return
+
+  const { data: user, error } = await useFetch('/api/auth/me', {
+    headers: useRequestHeaders(['cookie']),
+  })
+
+  if (error.value?.statusCode === 401 || !user.value) {
+    return navigateTo('/admin/login')
+  }
+
+  if (user.value.role !== 'admin') {
+    return navigateTo('/')
+  }
+})