scanner: fix library isolation, file mtime, force rescan, and deletion handling

Fix 1 - File modification time for created_at:
- Get file.ModTime() in processMediaFile and pass to CreateMediaItem
- Modified SQL INSERT to include created_at column

Fix 2 - Force rescan UPDATE instead of DELETE+INSERT:
- Changed force rescan logic to call updateMediaItem instead of delete + create
- Preserves created_at timestamp on force rescan

Fix 3 - GetMediaItemByFilePath filters by library_id:
- Added library_id to WHERE clause in SQL query
- Created GetMediaItemByFilePathAnyLibrary for cross-library lookups (KOReader)
- Added SetLibraryID method to MediaScanner
- Updated handler to call SetLibraryID for watch mode

Fix 4 - File deletion handling with persistent logging:
- Added fsnotify.Remove handler in WatchChanges
- Added orphan cleanup in ScanFolders after scan completes
- Created scanner_logger.go with daily log rotation (7 days)
- Logs to /app/logs/scanner-deletes-YYYY-MM-DD.log and scanner-errors-YYYY-MM-DD.log
- Individual deletes with enhanced safety logging

Note: Integration tests can now safely scan /app/uploads because
GetMediaItemByFilePath now filters by library_id, preventing
cross-library interference.

bruno/library/Update Scan Settings.yml

@@ -2,17 +2,27 @@ info:
   name: Update Scan Settings
   type: http
   seq: 1
+
 http:
   method: PUT
-  url: '{{base_url}}/api/library/scan-settings'
-  auth: inherit
+  url: "{{base_url}}/api/libraries/scan-settings"
+  headers:
+    - name: ""
+      value: application/json
   body:
     type: json
-    jsonBody: "{\n    \"scan_frequency_minutes\": 60,\n    \"auto_scan_enabled\":\
-      \ true"
-  headers:
-  - key: Content-Type
-    value: application/json
+    data: |-
+      {
+        "scan_frequency_minutes": 30,
+        "auto_scan_enabled": true
+      }
+  auth: inherit
+
+settings:
+  encodeUrl: true
+  timeout: 0
+  followRedirects: true
+  maxRedirects: 5
 
 docs: |-
   ## Update Scan Settings