Show scan overlay after page reload

- Add is_scanning state tracking in AnimeService
- Add get_scan_status method to AnimeService
- Add /api/anime/scan/status endpoint to check scan state
- Add checkActiveScanStatus in JS to restore overlay on reconnect
- All 1024 tests passing

data/config.json

@@ -17,7 +17,8 @@
     "keep_days": 30
   },
   "other": {
-    "master_password_hash": "$pbkdf2-sha256$29000$bY3xHiPkPCckJMT4H8PY2w$s7wlQnFrLpXdGE4GhX5hgZGSHka4SsuAchcFN5qBx3k"
+    "master_password_hash": "$pbkdf2-sha256$29000$NkbIuZfSGiMEAGDMWau1tg$pMLf3tp4uH36YeG3KBgkX3F00dwbN2dGPQCWNvrjhnU",
+    "anime_directory": "/mnt/server/serien/Serien/"
   },
   "version": "1.0.0"
 }

data/config_backups/config_backup_20251224_210530.json

@@ -17,7 +17,8 @@
     "keep_days": 30
   },
   "other": {
-    "master_password_hash": "$pbkdf2-sha256$29000$CMG4t9a6t9Y6J2TMOYfQ2g$bUIhqeewMMSj2Heh07vIhAGjvzDVijHb62aes4JuJhw"
+    "master_password_hash": "$pbkdf2-sha256$29000$GKP0fo.RspaScm5trRWiFA$cEeWdNCea5O7PAF21LyHVK.Xxj8sw3/9bbEdapRbCrw",
+    "anime_directory": "/mnt/server/serien/Serien/"
   },
   "version": "1.0.0"
 }