fix(venue-crowd): retry renderer binding + preserve mid-stinger transitions

Codex preflight P2s: (1) videos created before highway_3d registered its
globals never reached the backdrop planes — binding is now idempotent and
retried from start/perf-event/re-activation paths; (2) a crowd-state
switch committing while a stinger played was dropped because the machine
had already advanced — it is now deferred and played when the stinger ends.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

static/v3/venue-scene-3d.js

@@ -96,6 +96,7 @@
         if (_active) {
             syncInstrumentPov();
             syncVenueMotion();
+            syncCrowd(true);
             return;
         }
         _active = true;