Mitigate CI cache timeouts and wire venue door-staff dialogue

- Drop actions/cache@v4 from the checks job: the Gitea runner cannot reach
  GitHub's cache service (/twirp/...CacheService timeouts, ~2min retries);
  Godot import is fast enough without it. Add GODOT_SILENCE_ROOT_WARNING=1.
- Document the cache situation and re-enable path in docs/RELEASING.md
- VenueScenario.door_staff_line(context, rng): seeded-random venue lines
- GameManager logs id/ticket/wand-check, refusal, and prohibited-item lines
  from the venue scenario (Joke Shop flavor) during inspection/screening
- Test coverage: all Joke Shop contexts, unknown contexts, empty venues,
  deterministic seeded picks (54 tests pass)

src/core/venue_scenario.gd

@@ -68,6 +68,23 @@ func _spot_for_intent(intent: String) -> String:
 		_:
 			return "sidewalk"
 
+## Pick a random door-staff line for a context key (e.g. "id_check",
+## "ticket_check", "wand_check", "refusal", "prohibited_item"). Returns ""
+## when the venue has no lines for that context. Deterministic when a seeded
+## RNG is injected; otherwise returns the first line.
+func door_staff_line(context: String, rng: RandomNumberGenerator = null) -> String:
+	if not door_staff_lines.has(context):
+		return ""
+	var lines: Variant = door_staff_lines[context]
+	if not (lines is Array):
+		return ""
+	var pool: Array = lines
+	if pool.is_empty():
+		return ""
+	if rng != null:
+		return str(pool[rng.randi_range(0, pool.size() - 1)])
+	return str(pool[0])
+
 func _location_or_default(spot: String, fallback: Vector3) -> Vector3:
 	if locations.has(spot):
 		var v: Variant = locations[spot]