Add the first-shift tutorial design and state machine

Write the eight-beat tutorial sheet, its safe visitor script, persistence and
replay rules. Add a deterministic, skippable/restartable Tutorial RefCounted
state machine with headless tests. UI/GameManager wiring remains the next task.
Headless 235/235, Python 94/94.

docs/gameplay.md

@@ -16,6 +16,8 @@ A typical shift lasts 10–15 minutes. The player:
 
 The game rewards calm resolutions rather than aggressive behavior. Emergency assistance and armed responders are rare last-resort systems with meaningful consequences.
 
+The first shift starts with an in-game tutorial covering movement/look, focus cycling, the action wheel, access inspection, polite direction, formal warning/body camera, radio and shift review. Its beat sheet is in [`tutorial.md`](tutorial.md).
+
 ## Venues
 
 ### Hollywood Boulevard Building