Runtime hygiene: fix RefCounted cycles (clean suite exit), full-length shifts, wand cooldown

- FSM holds owner via WeakRef; ShiftCoordinator is RefCounted (logic-only);
  persistence tests free the Save node -> test suite exits with zero
  'resources still in use' warnings (was ~13) and 57/57 pass
- GameManager uses each scenario's shift_duration_s (900s ~ 10-15 min) for
  real shifts instead of the 300s test duration
- Wand screening gets a 0.8s recharge cooldown with a wand.recharge message
- TODO/DONE/MEMORY/README synced

TODO.md

@@ -42,15 +42,11 @@ Goal: a single executable `.AppImage` that runs the full game on any recent dist
 ## Future Systems (design-level backlog)
 
 - [ ] Body-camera replay timeline in the shift review.
-- [ ] Long (10-15 minute) shift lengths (phase lighting already implemented).
 - [ ] Venue selection startup menu (keyboard cycling with `V` is implemented).
 - [ ] IDE/editor-based GUT integration when a Godot editor workflow is introduced.
-- [ ] Reduce RefCounted reference cycles (NPCController <-> FSM) noted in `MEMORY.md`.
 
 ## Open Polish
 
-- [ ] Add a body/wand cooldown feel: wand screening currently has no reuse penalty; consider a
-      short per-guest scan animation.
 - [ ] Keep `%` placeholders stable in `Strings.fmt` when adding keys (positional formatting).
 
 ## Detailed Graphics — remaining performance items