feat: add WD tagger, remove caption UI, add per-image tag queuing in lightbox
- Add WD SwinV2 tagger v3 backend (tagger.rs) with DirectML acceleration
- Expose tagger commands (model status, download, queue, tags CRUD)
- Add queueTaggingForImage store action and AI tags button in lightbox sidebar
- Remove all caption UI surfaces (Lightbox, BackgroundTasks, SettingsModal)
- Disable caption worker in lib.rs; keep Rust backend intact for future use
- Make lightbox sidebar scrollable with sticky header/footer
- Collapse long tag lists (show 8, expandable) in lightbox sidebar
LyAhn
a9dd2b2797