feat: implement auth middleware, user sync, and token state persistence

- Define useAuth composable logic with syncUser, handleLoginSuccess, and logout methods
- Add auth.ts and guest.ts route middlewares to guard routes based on authentication and user roles
- Add auth.client.ts plugin to boot-sync logged in user details
- Declare custom PageMeta type definitions to support role-based authorization rules

app/plugins/auth.client.ts

@@ -0,0 +1,16 @@
+export default defineNuxtPlugin(async () => {
+  const auth = useAuth()
+
+  if ((auth.token.value || auth.tokenState.value) && !auth.user.value) {
+    try {
+      await auth.syncUser()
+    } catch (error) {
+      console.error('[Auth Plugin] Sync failed:', error)
+      auth.logout()
+    }
+  }
+
+  console.log('[Auth Plugin] Initialized - User:', auth.user.value?.id || 'None', 'Authenticated:', auth.isAuthenticated.value)
+})
+
+