Save The Tree implementation and acceptance work in progress

Preserve production code, regression fixtures, audio assets and provenance, test infrastructure, and the original-completion plan and progress ledger. Final game and Windows acceptance remain pending; excluded local artifacts and native experiments are not part of this snapshot.

tests/ui/test_supply_management.gd

@@ -1,5 +1,7 @@
 extends SceneTree
 
+const AudioTeardown := preload("res://tests/helpers/ui_audio_teardown.gd")
+
 ## Normal build/purchase commands: UI drafts, money/stock reconciliation, queued
 ## purchases and an isolated save slot. No free inventory is inserted.
 var _checks := 0
@@ -52,7 +54,7 @@ func _run() -> void:
 	_panel = _main.find_child("SupplyManagementPanel", true, false) as SupplyManagementPanel
 	_expect(_panel != null, "normal scene includes supply management")
 	if _panel == null:
-		_finish()
+		await _finish()
 		return
 	(_main.get("navigation_buttons")[&"product"] as Button).pressed.emit()
 	_expect(_panel.visible and _panel.purchase_button.disabled, "product opens a safe empty state before any warehouse exists")
@@ -75,7 +77,7 @@ func _run() -> void:
 			_kitchens.append(facility.instance_id)
 	_expect(not _warehouse.is_empty() and _kitchens.size() == 2, "paid construction produces a warehouse and two kitchens")
 	if _warehouse.is_empty() or _kitchens.size() != 2:
-		_finish()
+		await _finish()
 		return
 	_main.call("_activate_management_mode", &"product")
 	_panel.refresh()
@@ -85,7 +87,7 @@ func _run() -> void:
 	_test_kitchen_drafts()
 	_test_saved_pending_purchase()
 	await _test_navigation_and_layout()
-	_finish()
+	await _finish()
 
 
 func _test_purchase_and_failure() -> void:
@@ -259,7 +261,7 @@ func _expect(condition: bool, message: String) -> void:
 
 func _finish() -> void:
 	SaveService.delete_save(_save_path)
-	if is_instance_valid(_main):
-		_main.queue_free()
+	var teardown: Dictionary = await AudioTeardown.free_owner_and_wait(self, _main)
+	_expect(bool(teardown.get(&"passed", false)) and not bool(teardown.get(&"deadline_reached", true)), "owned audio references release before bounded teardown deadline with whole Runtime unchanged")
 	print("Supply management UI: %d checks, %d failures" % [_checks, _failures])
 	quit(1 if _failures > 0 else 0)