feat: auto check-in on barcode scan of existing assets

- handleBarcode() now calls autoCheckin() after finding asset via barcode
- showScannedAsset() no longer shows manual checkin card
- Replace 'Check In' button with 'Auto checked in' indicator
- Add CSS for sr-checkin-done span

server.py

@@ -13,6 +13,8 @@ import os
 import re
 import secrets
 import sqlite3
+import urllib.error
+import urllib.request
 import uuid
 from contextlib import asynccontextmanager
 from pathlib import Path