- New store.VoidLatestFact() method finds latest non-voided fact for
a key and writes a void-marker row pointing at it (transactional).
- New IPC method MethodRevertFact with CoreAPI.RevertFact interface,
storeAPI adapter, server dispatch, and client proxy.
- New HTTP endpoint POST /api/revert?key=<key> in mavweb.
- History page adds a 'revert' button per non-voided fact row with
JS confirmation and optimistic UI (marks row voided on success).
- All existing store, IPC, and mavweb tests pass.
- New /history route displays recent facts in a dedicated page with
voided-row styling (line-through + opacity + badge).
- Navigation link added to /dash page header.
- Handler calls core.RecentFacts(ctx, 200) and renders historyTmpl.
kami