docs: portrait admin screenshots + user guide admin section

- Retake all admin screenshots in portrait (412px narrow column)
- Add Admin Panel section (Section 9) to USER_GUIDE.md
- Update ADMIN_GUIDE.md references for portrait screenshots

docs/USER_GUIDE.md

@@ -12,6 +12,7 @@
 6. [Working with Geofences (Service Areas)](#6-working-with-geofences-service-areas)
 7. [Viewing Reports & Dashboard](#7-viewing-reports--dashboard)
 8. [Tips & Troubleshooting](#8-tips--troubleshooting)
+9. [Admin Panel](#9-admin-panel)
 
 ---
 
@@ -199,3 +200,21 @@ Access the drawer menu (**⋯ More**) → **Dashboard** for a full view.
 
 > **Pro tip:** For the best mobile experience, add the app to your home screen:
 > Chrome → Menu → **Add to Home Screen**. It opens like a native app!
+
+---
+
+## 9. Admin Panel
+
+The **Admin Panel** at [admin.canteen.ourpad.casa](https://admin.canteen.ourpad.casa) provides management tools for:
+
+- **Dashboard** — Overview of all assets, check-ins, customers, and users
+- **Settings** — Manage categories, makes/models, key types, badge types
+- **Users** — Create and manage user accounts with role-based access
+- **Customers** — Manage customer accounts and locations
+- **Activity Log** — Full audit trail with filters and pagination
+- **Export** — Export asset and check-in data as CSV
+- **Import** — Upload Excel files to import asset data
+
+![Admin Dashboard](images/p9a_admin_dashboard.png)
+
+> See the **[Admin Guide](ADMIN_GUIDE.md)** for full documentation.