OneFolder does not detect externally modified XMP metadata (Tags)

[cspius]

Describe the bug
OneFolder does not automatically re-index files when embedded metadata (EXIF/XMP) is modified externally and synchronized via Syncthing. Tags written by Aves Libre on Android are not detected after sync.

To Reproduce
Steps to reproduce the behavior:
1. Add photos to a OneFolder-managed directory on macOS
2. Sync the directory to an Android phone using Syncthing
3. Open the photo in Aves Libre on Android
4. Add or modify tags (written directly into the file’s XMP metadata)
5. Let Syncthing synchronize the modified file back to the MacBook
6. Open or refresh OneFolder

Expected behavior
OneFolder should detect that the file has changed and automatically re-read the updated EXIF/XMP metadata, showing the new tags without requiring a manual full re-index.

Actual behavior
OneFolder does not show the updated tags. The changes only appear after manually re-indexing the entire library or affected folder.

OneFolder version: v1.1.2
Desktop OS macOS Tahoe 26.2

Additional context
• Aves Libre writes tags directly into the image file (embedded XMP), not to a separate database or sidecar
• Syncthing correctly synchronizes the modified file; the updated metadata is visible using ExifTool and other metadata-aware tools on macOS
• In general, Aves Libre and OneFolder work well together when indexing from scratch. The issue only occurs when metadata changes happen after the initial OneFolder index
• This suggests OneFolder may not be reacting to external file content changes (e.g. relying on cached metadata or missing filesystem change events)