Add body-camera timeline to the shift review

- New src/game/ui/event_timeline.gd flattens every recorded incident event
  (ADR-0005) into one time-ordered list and shows time, person, and a one-line
  summary. Step with Left/Right or the buttons; Esc returns to the review. No live
  3D replay in this first version.
- Shift review gains a "Body camera timeline" button that hands the review to the
  timeline; the review dim is hidden while it is open (stacked overlays made the
  screen nearly black) and restored on close.
- ShiftCoordinator records started_at_ms so the review can stamp events as mm:ss.
- 8 new string keys for the timeline UI and the review button.

Tests/docs
- Headless suite 113 -> 120 (test_event_timeline.gd), new smoke_timeline.gd that
  opens the timeline from the review, steps through every event, and closes back.
- README, TODO section moved to DONE, MEMORY notes. Version 0.2.6.

TODO.md

@@ -1,16 +1,11 @@
 # TODO
 
-Godot 4.3 prototype. Release **v0.2.5** is tagged. Headless suite **113/113**, plus
-`smoke_session_shell.gd`, `smoke_plan_verbs.gd`, `smoke_crowd.gd`, `smoke_emergency.gd`, and the
-windowed focus/radial smoke.
+Godot 4.3 prototype. Release **v0.2.6** is tagged. Headless suite **120/120**, plus
+`smoke_session_shell.gd`, `smoke_plan_verbs.gd`, `smoke_crowd.gd`, `smoke_emergency.gd`,
+`smoke_timeline.gd`, and the windowed focus/radial smoke.
 
 Host `REQUIRE_SIGNIN_VIEW` stays deferred.
 
-## Body-camera replay
-
-- [ ] Shift review: a timeline of recorded incident events (ADR-0005 already stores them).
-      Scrub or step through; no live 3D replay required in the first version.
-
 ## NPC theater
 
 Intents `sit` / `photo` / `film` / `perform` already pick waypoints. ADR-0010 rig (face/hair)