Implement prototype: venue-driven simulation core, scenarios, tests, and playable entrance scene

- Godot 4.3 project scaffold with first-person guard, procedural world,
  interaction HUD, access inspection, radio forms, debug overlay, shift review
- Simulation core: ShiftCoordinator, VenueScenario, EventScheduler, NPCController/FSM,
  AccessVerifier, EscalationManager, RadioSystem, IncidentRecorder,
  ReputationEvaluator, CrowdSystem, EventBus
- Three authored scenarios (Hollywood Blvd building, The Joke Shop, TV studio)
- Custom headless test runner (25 tests) replacing editor-dependent GUT,
  plus GitHub Actions CI
- Documentation workflow live: README, PLAN (tech stack), TODO/DONE, MEMORY

src/test/test_runner.gd

@@ -0,0 +1,73 @@
+extends SceneTree
+## Minimal headless test runner for CI (used in place of an editor-based addon
+## until a Godot editor workflow is introduced).
+##
+## Usage:
+##   godot --headless --path . --script res://src/test/test_runner.gd
+## Exit code 0 = all passed, 1 = failures.
+
+const TestUtils := preload("res://src/test/test_utils.gd")
+const TEST_DIR := "res://src/test/tests"
+
+func _initialize() -> void:
+	var test_files := _list_gd_files(TEST_DIR)
+	var total_passed := 0
+	var total_failed := 0
+	var failures: Array[String] = []
+
+	for path in test_files:
+		var script: GDScript = load(path)
+		if script == null:
+			failures.append("Could not load %s" % path)
+			total_failed += 1
+			continue
+		var instance: Object = script.new()
+		TestUtils.reset()
+		var suite_passed := 0
+		var suite_failed := 0
+		for method_info in instance.get_method_list():
+			var method: StringName = method_info["name"]
+			if not String(method).begins_with("test_"):
+				continue
+			if method_info["flags"] & METHOD_FLAG_STATIC:
+				continue
+			TestUtils.reset()
+			var result: Variant = instance.call(method)
+			var errored: bool = TestUtils._errors.size() > 0
+			if result == true and not errored:
+				suite_passed += 1
+			else:
+				suite_failed += 1
+				var detail := ""
+				if errored:
+					detail = " :: " + TestUtils.report()
+				failures.append("%s.%s%s" % [path.get_file(), method, detail])
+		total_passed += suite_passed
+		total_failed += suite_failed
+		print("Suite %-42s pass=%d fail=%d" % [path.get_file(), suite_passed, suite_failed])
+
+	print("")
+	print("==================== TEST SUMMARY ====================")
+	print("Passed: %d   Failed: %d" % [total_passed, total_failed])
+	if failures.size() > 0:
+		print("--------------------------------------------------")
+		for f in failures:
+			print("FAIL: %s" % f)
+	print("======================================================")
+	quit(0 if total_failed == 0 else 1)
+
+func _list_gd_files(dir_path: String) -> Array[String]:
+	var out: Array[String] = []
+	var dir := DirAccess.open(dir_path)
+	if dir == null:
+		push_error("Cannot open test dir %s" % dir_path)
+		return out
+	dir.list_dir_begin()
+	var file_name := dir.get_next()
+	while file_name != "":
+		if not dir.current_is_dir() and file_name.ends_with(".gd"):
+			out.append(dir_path.path_join(file_name))
+		file_name = dir.get_next()
+	dir.list_dir_end()
+	out.sort()
+	return out