Image_lib.php fixes:
- Remove incorrect 'GPS' => PelTag::GPS_OFFSET mapping (GPS handled separately)
- Fix PNG transparency: change imagealphablending to false
- Add animated GIF detection: skip processing for animations
- Add logging in stripExifFallback to show which APP markers are removed
Migration optimization:
- Use get()->getRow() instead of countAllResults() for lighter query
- More efficient existence check before insert
All changes address CodeRabbit technical review comments while maintaining
the simplified multiselect-only UI (no toggle needed).
a55885de87