fix: 修复欢迎板和通知板通知无法关闭问题

- 修复欢迎板和通知板当前被ChatUI 抢占鼠标问题，通过设置启动弹窗时ChatUI 根节点 mouse_filter 临时改为 IGNORE来实现
- ToDo: 后续统一规划事件逻辑

scenes/ui/WelcomeDialog.gd

@@ -1,6 +1,12 @@
 extends CanvasLayer
 
+var _chat_ui: Control
+var _chat_ui_prev_mouse_filter: int = Control.MOUSE_FILTER_STOP
+var _chat_ui_mouse_disabled: bool = false
+
 func _ready():
+	_disable_chat_ui_mouse_input()
+
 	# Connect close button (X)
 	var header_close = find_child("CloseButton", true, false)
 	if header_close:
@@ -11,6 +17,9 @@ func _ready():
 	if start_btn:
 		start_btn.pressed.connect(_on_close_pressed)
 
+func _exit_tree():
+	_restore_chat_ui_mouse_input()
+
 func _on_close_pressed():
 	queue_free()
 
@@ -18,3 +27,23 @@ func _input(event):
 	# Allow ESC to close
 	if event.is_action_pressed("ui_cancel"):
 		queue_free()
+
+func _disable_chat_ui_mouse_input():
+	var current_scene = get_tree().current_scene
+	if current_scene:
+		_chat_ui = current_scene.get_node_or_null("UILayer/ChatUI") as Control
+
+	if _chat_ui == null:
+		_chat_ui = get_tree().root.find_child("ChatUI", true, false) as Control
+
+	if _chat_ui:
+		_chat_ui_prev_mouse_filter = _chat_ui.mouse_filter
+		_chat_ui.mouse_filter = Control.MOUSE_FILTER_IGNORE
+		_chat_ui_mouse_disabled = true
+
+func _restore_chat_ui_mouse_input():
+	if _chat_ui_mouse_disabled and is_instance_valid(_chat_ui):
+		_chat_ui.mouse_filter = _chat_ui_prev_mouse_filter
+
+	_chat_ui_mouse_disabled = false
+	_chat_ui = null