- Add PreviewPanel dispatch hub routing by entity_kind + artifact extension
- VideoPreview: HTML5 <video> for YouTube/Instagram/TikTok/Reddit/X posts
- TweetPreview: tweet card, thread, and X article renderer (ported from x-article-renderer)
- IframePreview: sandboxed iframe for SingleFile web pages and PDFs
- ImagePreview: image viewer with click-to-open-fullsize
- AudioBar: persistent fixed-bottom player (Spotify-style) that survives entry navigation
- Lift entryDetail to App.jsx, shared between PreviewPanel and ContextRail
- 3-column layout (workspace | 300px preview | 340px rail) when preview active
- Stale-guard fixes: seq incremented before early returns in all async effects
- handleRearchive: capture startSeq/entryUid at call time, guard every async resume
- TweetPreview: reset loading/error/tweets before early-return branches
