P14-03: Versioned shaft-wait saves, keep riders aboard, real-actor proof

- ElevatorService snapshot v2 carries the shaft-wide wait; v1 saves (written
  with every elevator dynamic_cost 0) migrate by deriving it on load, and any
  v2 mismatch, including all zeros, is rejected atomically. A genuine save
  from 50ceca0 is kept as tests/fixtures/p14-03/legacy_rush_v1.
- A guest aboard a cabin no longer decides, leaves or despawns until the
  elevator sets it down at a real landing; previously a rider told to leave
  vanished from a moving cabin.
- test_route_wait_choice now proves the rush detour and route loss with a
  worker who actually walks, every shared rider's arrival cell, service
  elevator and stair congestion, legacy migration and a new-PID restart.
- Register completion markers for the seven suites added this session and
  bring the P14 ledger in line with P14-02's completion.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/plans/original-completion-2026-10-02/progress_snapshot.json

@@ -156,8 +156,8 @@
   },
   "current_delivery_state_counts": {
     "completed": 21,
-    "in_progress": 19,
-    "planned": 48
+    "in_progress": 20,
+    "planned": 47
   },
   "completed_current_deliveries": [
     "P00-01",