feat(client): 完成40250客户端核心功能1:1对齐与桥梁高度采样修复

- 桥梁与静态物体高度采样修复：
  - 严格对齐 40250 CMapOutdoor::GetHeight 与 CAttributeInstance::GetHeight
  - 解析 .mdatr 中的 AttributeHeight 网格，使用 is_in_triangle_2d 准确计算桥面多边形平面方程
  - sample_height 查询邻近区块并返回 fMAX(fObjectHeight, fTerrainHeight)，彻底解决走上桥面穿透掉入水底/河床的问题
  - 新增 test_bridge_height_parity.gd 自动化对拍测试
- 40250 怪物击杀经验动效：
  - 1:1 实现 FLY_EXP(0) / FLY_HP / FLY_SP 粒子轨迹与爆炸吸附
- 40250 客户端全系统功能对齐（Batches 1-31）：
  - 包含公会、交易、骑乘、变身、钓鱼、采矿、商城、信件、结婚、地牢等 134 套对拍系统与自动化回归测试
- 文档沉淀：
  - 新增 docs/CLIENT-PARITY-AUDIT-AND-FIX-GUIDE.md 客户端对拍缺陷发现与修复工程指南

project/ui/system_option_ui.gd

@@ -66,6 +66,11 @@ func setup(ui_manager: CanvasLayer, assets: String, audio_node: Node = null,
 	uiscript_dir = assets_root.path_join("uiscript/uiscript")
 	if not DirAccess.dir_exists_absolute(uiscript_dir):
 		uiscript_dir = assets_root.path_join("uiscript")
+	if ui and ui.has_signal("window_closed"):
+		ui.window_closed.connect(func(w):
+			if not _win.is_empty() and _win.get("root") == w:
+				_win = {}
+		)
 	audio = audio_node
 	_cam_get = cam_getter
 	_env_get = env_getter
@@ -80,7 +85,9 @@ func is_open() -> bool:
 	return not _win.is_empty() and is_instance_valid(_win.get("root"))
 
 func set_mobile_mode(enabled: bool) -> void:
-	if not enabled and _mobile_root != null:
+	if enabled == _mobile_mode:
+		return
+	if is_open():
 		var old_mode := _mobile_mode
 		_mobile_mode = true
 		close()
@@ -97,9 +104,10 @@ func close() -> void:
 			ui.close(_mobile_root)
 		_mobile_root = null
 		return
-	if is_open():
-		ui.close(_win["root"])
+	var r: Control = _win.get("root", null)
 	_win = {}
+	if r and is_instance_valid(r) and ui:
+		ui.close(r)
 
 func open() -> void:
 	if _mobile_mode:
@@ -111,13 +119,35 @@ func open() -> void:
 	if not FileAccess.file_exists(path):
 		push_warning("SystemOptionUI: no systemoptiondialog.py at " + path)
 		return
-	_win = ui.open_script(path, assets_root)
+	_win = ui.open_script(path, assets_root, false, true)
 	if not is_open():
 		return
+	set_center_position()
 	_relabel()
 	_wire()
 	_sync_controls()
 
+## 1:1 对齐 40250 uisystemoption.py: self.SetCenterPosition()
+func set_center_position(offset := Vector2.ZERO) -> void:
+	var r: Control = _win.get("root", null)
+	if r == null or not is_instance_valid(r):
+		return
+	if ui and ui.has_method("center_window"):
+		ui.center_window(r, offset)
+	else:
+		var vp_sz := Vector2(1920, 1080)
+		var vp := r.get_viewport()
+		if vp:
+			var vrect := vp.get_visible_rect().size
+			if vrect.x > 300 and vrect.y > 300:
+				vp_sz = vrect
+		elif ui and "screen" in ui and ui.screen.x > 0:
+			vp_sz = Vector2(ui.screen)
+		var sz := r.size
+		if sz.x <= 0 or sz.y <= 0:
+			sz = r.custom_minimum_size
+		r.position = ((vp_sz - sz) / 2.0 + offset).round()
+
 func _open_mobile() -> void:
 	if is_open():
 		return
@@ -255,6 +285,10 @@ func _wire() -> void:
 	var bgm_btn := _node("bgm_button")
 	if bgm_btn is BaseButton:
 		bgm_btn.disabled = true   # 换 BGM 需音乐文件选择器，暂缺
+	var tb := _node("titlebar")
+	if tb:
+		for x in tb.find_children("*", "BaseButton", true, false):
+			x.pressed.connect(close)
 
 func _bind_radio(names: Array, on_pick: Callable) -> void:
 	var boxes: Array = []