Show total items to scan in progress overlay

- Add total_items parameter to broadcast_scan_started and broadcast_scan_progress
- Pass total from SeriesApp to WebSocket broadcasts in AnimeService
- Update JS overlay to show progress bar and current/total count
- Add CSS for progress bar styling
- Add unit tests for new total_items parameter
- All 1024 tests passing

data/config_backups/config_backup_20251224_205327.json

@@ -17,8 +17,7 @@
     "keep_days": 30
   },
   "other": {
-    "master_password_hash": "$pbkdf2-sha256$29000$RYgRIoQwBuC8N.bcO0eoNQ$6Cdc9sZvqy8li/43B0NcXYlysYrj/lIqy2E7gBtN4dk",
-    "anime_directory": "/mnt/server/serien/Serien/"
+    "master_password_hash": "$pbkdf2-sha256$29000$CMG4t9a6t9Y6J2TMOYfQ2g$bUIhqeewMMSj2Heh07vIhAGjvzDVijHb62aes4JuJhw"
   },
   "version": "1.0.0"
 }