Improve scan overlay UX

- Show overlay immediately when rescan is clicked (before API response)
- Add click-outside-to-close on overlay background
- Add click on rescan-status indicator to reopen overlay
- Add cursor pointer to rescan-status for clickability feedback
- All 1024 tests passing

data/config_backups/config_backup_20251224_210928.json

@@ -1,24 +0,0 @@
-{
-  "name": "Aniworld",
-  "data_dir": "data",
-  "scheduler": {
-    "enabled": true,
-    "interval_minutes": 60
-  },
-  "logging": {
-    "level": "INFO",
-    "file": null,
-    "max_bytes": null,
-    "backup_count": 3
-  },
-  "backup": {
-    "enabled": false,
-    "path": "data/backups",
-    "keep_days": 30
-  },
-  "other": {
-    "master_password_hash": "$pbkdf2-sha256$29000$tTYmJCSEUArhnLN2TmktpQ$mhMKshEetPJfjRqYYUUvOGNRxcnIMNIto73IRKw4hPM",
-    "anime_directory": "/mnt/server/serien/Serien/"
-  },
-  "version": "1.0.0"
-}

data/config_backups/config_backup_20251224_212619.json

@@ -17,7 +17,7 @@
     "keep_days": 30
   },
   "other": {
-    "master_password_hash": "$pbkdf2-sha256$29000$GKP0fo.RspaScm5trRWiFA$cEeWdNCea5O7PAF21LyHVK.Xxj8sw3/9bbEdapRbCrw",
+    "master_password_hash": "$pbkdf2-sha256$29000$tpaSEqI0BmCMsbb2HgOA0A$zF52br5qvqyA2ciQlDt7.Cdny2d2qaq1BPqNEntoMeY",
     "anime_directory": "/mnt/server/serien/Serien/"
   },
   "version": "1.0.0"