feat(ui): first-class undo/redo buttons in combat controls

Undo/redo pills in InitiativeControls, always visible when encounter open.

- Undo = latest non-undone log for this encounter, applies undo.updates.
- Redo = latest undone log, applies undo.redo (forward patch).
- encounterPath added to all 14 logAction contexts (filter key).
- redo:patch added to undoData so redo replays real forward state.
- Disabled when stack empty. Tooltip shows target action message.
- Uses current 2-write undo (non-tx). Race safety deferred to FEAT-LOG.

TODO updated. 84 FE tests green.

TODO.md

@@ -8,7 +8,7 @@ Backlog of bugs + long-term items. Milestones live in REWORK_PLAN.md.
 - Ambiguous label. May expand work based on what NPC means here (ally? monster?
   display-only? skip in turn order?). Clarify intent before UX changes.
 
-### FEAT: first-class undo/redo UI buttons (B — do now)
+### FEAT: first-class undo/redo UI buttons (B --- do now)
 - Toolbar buttons ↶/↷ in AdminView header, not buried in /logs.
 - Undo = revert latest non-undone log. Redo = re-apply latest undone.
 - Uses current 2-write undo (non-tx). Race safety = log refactor later.
@@ -27,8 +27,23 @@ Backlog of bugs + long-term items. Milestones live in REWORK_PLAN.md.
 - replay-combat + analyze-turns rewritten to emit/consume same event shape.
 - Migration: keep old log entries readable; new format for new writes.
 
+
+## FEAT - parallel campaigns
+
+## FEAT - multi user
+
+## FEAT - clarify what end encounter does and what initiatives reset means
+
 ## Done (history)
 
+### FEAT: first-class undo/redo UI buttons (DONE)
+- ↶/↷ pills in InitiativeControls, always visible when encounter open.
+- Undo = latest non-undone log (per encounter). Redo = latest undone.
+- encounterPath added to all 14 log contexts (filter key).
+- redo:patch (forward) added to undoData. Real redo replays forward state.
+- Disabled when stack empty. Tooltip shows target action.
+- Uses current 2-write undo (non-tx). Race safety = FEAT-LOG refactor.
+
 ### Architecture: 1-list turn order model (slot, never sort)
 - Single source: turnOrderIds === participants.map(id). No re-sort after
   startEncounter. nextTurn skips inactive (predicate), inactive stay in slot.