Align catalog with Bambu Lab product line, add conditional filters and admin sidebar

- Add master catalog (bambuLabCatalog.ts) as single source of truth for materials, finishes, colors, and refill/spool availability
- Fix incorrect finish-per-material mappings (remove PLA: 85A/90A/95A HF/FR/GF/HF, add ASA: Basic/CF/Aero, fix PETG/PC)
- Implement cascading filters on public site: material restricts finish, finish restricts color
- Add AdminSidebar component across all admin pages
- Redirect /upadaj to /dashboard when already authenticated
- Update color hex mappings and tests to match official Bambu Lab names

app/upadaj/page.tsx

@@ -12,6 +12,15 @@ export default function AdminLogin() {
   const [error, setError] = useState('');
   const [loading, setLoading] = useState(false);
 
+  // Redirect to dashboard if already authenticated
+  useEffect(() => {
+    const token = localStorage.getItem('authToken');
+    const expiry = localStorage.getItem('tokenExpiry');
+    if (token && expiry && Date.now() < parseInt(expiry)) {
+      window.location.href = '/dashboard';
+    }
+  }, []);
+
   // Set dark mode by default
   useEffect(() => {
     document.documentElement.classList.add('dark');