AssetManager 0.5.5.68

Changes

Improved the reusable asset/category image library.
- The persistent data/uploads/library directory is scanned directly whenever an asset or category form is opened.
- Supported image files copied manually to the Docker host are available after reloading the form.
- Subdirectories are scanned recursively and displayed using their relative path.
- Symbolic links are ignored so the configured library root cannot be escaped.
Improved duplicate highlighting in dark mode.
- Duplicate rows keep the existing yellow background.
- Text, links and secondary text use a dark foreground color for sufficient contrast.

No database migration is required. Existing asset/category image references and duplicate-search logic remain unchanged.