fix: 装备属性面板避让逻辑 + 多项功能更新

- item_tooltip_view.gd: 新增 avoid_rect 属性，tooltip 与装备窗口重叠时自动推到左侧
- inventory_ui.gd: 悬停装备时传入窗口矩形作为避让区域
- 包含其他累积的功能开发和测试文件

project/app_lifecycle.gd

@@ -47,8 +47,10 @@ func _notification(what: int) -> void:
 		NOTIFICATION_APPLICATION_RESUMED:
 			_exit_background()
 		NOTIFICATION_APPLICATION_FOCUS_IN, NOTIFICATION_WM_WINDOW_FOCUS_IN:
+			_exit_background()
 			focus_changed.emit(true)
 		NOTIFICATION_APPLICATION_FOCUS_OUT, NOTIFICATION_WM_WINDOW_FOCUS_OUT:
+			_enter_background()
 			focus_changed.emit(false)
 		NOTIFICATION_OS_MEMORY_WARNING:
 			memory_warning.emit()
@@ -70,6 +72,8 @@ func _enter_background() -> void:
 		_bound_audio.save_volume()
 		if _bound_audio.has_method("set_music_volume"):
 			_bound_audio.set_music_volume(0.0)
+		if _bound_audio.has_method("set_sound_volume"):
+			_bound_audio.set_sound_volume(0.0)
 	elif _bound_audio and _bound_audio.has_method("stop_bgm"):
 		_bound_audio.stop_bgm()
 	if _bound_client and _bound_client.has_method("suspend"):