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/ui_manager.gd

@@ -33,9 +33,16 @@ var _last_mobile_area := Rect2(-1, -1, 0, 0)
 var _drag_win: Control = null
 var _drag_from := Vector2.ZERO
 
-func _ready() -> void:
+func _init() -> void:
+	layer = 10
+	_ensure_root()
+
+func _ensure_root() -> void:
+	if _root != null:
+		return
 	layer = 10
 	_root = Control.new()
+	_root.name = "UiRoot"
 	_root.set_anchors_preset(Control.PRESET_FULL_RECT)
 	_root.mouse_filter = Control.MOUSE_FILTER_IGNORE
 	add_child(_root)
@@ -51,6 +58,9 @@ func _ready() -> void:
 	_mobile_blocker.mouse_filter = Control.MOUSE_FILTER_STOP
 	_mobile_blocker.visible = false
 	_root.add_child(_mobile_blocker)
+
+func _ready() -> void:
+	_ensure_root()
 	set_process_input(true)
 	set_process_unhandled_input(true)
 	set_process(true)
@@ -121,16 +131,40 @@ func build_script(path: String, assets_root: String) -> Dictionary:
 		return {"root": Control.new(), "nodes": {}}
 	return UiBuild.build(spec, assets_root)
 
+## 1:1 对齐 40250 ui.py: SetCenterPosition(x = 0, y = 0)
+## 将窗口居中于当前屏幕 / 视口
+func center_window(win: Control, offset := Vector2.ZERO) -> void:
+	if win == null or not is_instance_valid(win):
+		return
+	var vp_sz := Vector2(1920, 1080)
+	var vp := win.get_viewport()
+	if vp:
+		var vrect := vp.get_visible_rect().size
+		if vrect.x > 300 and vrect.y > 300:
+			vp_sz = vrect
+	elif _root and _root.size.x > 300 and _root.size.y > 300:
+		vp_sz = _root.size
+	elif screen.x > 0 and screen.y > 0:
+		vp_sz = Vector2(screen)
+	var win_sz := win.size
+	if win_sz.x <= 0 or win_sz.y <= 0:
+		win_sz = win.custom_minimum_size
+	win.position = ((vp_sz - win_sz) / 2.0 + offset).round()
+
 # 解析 + 构建 + 打开，返回 { root, nodes }
-func open_script(path: String, assets_root: String, modal := false) -> Dictionary:
+func open_script(path: String, assets_root: String, modal := false, center := false) -> Dictionary:
 	var r := build_script(path, assets_root)
 	open(r.root, modal)
+	if center and r.root is Control:
+		center_window(r.root)
 	return r
 
 func open(win: Control, modal := false) -> void:
+	_ensure_root()
 	if win.get_parent() == null:
 		_root.add_child(win)
 	win.set_meta("modal", modal)
+	_wire_close_buttons(win)
 	if mobile_mode:
 		MobileWindowHost.install(win, _mobile_area(), _window_title(win),
 			Callable(self, "_close_hosted_window").bind(win))
@@ -141,6 +175,13 @@ func open(win: Control, modal := false) -> void:
 	_restack()
 	window_opened.emit(win)
 
+func _wire_close_buttons(win: Control) -> void:
+	for btn in win.find_children("CloseButton", "BaseButton", true, false):
+		var b := btn as BaseButton
+		if not b.has_meta("_close_wired"):
+			b.set_meta("_close_wired", true)
+			b.pressed.connect(func(): close(win))
+
 func close(win: Control) -> void:
 	if win == null:
 		return
@@ -383,19 +424,22 @@ func _close_mobile_popup() -> bool:
 # --- 标题栏拖动 --------------------------------------------------------
 
 func _wire_drag(win: Control) -> void:
-	var handle := _find_drag_handle(win)
-	if handle == null or handle.has_meta("_drag_wired"):
-		return
-	handle.set_meta("_drag_wired", true)
-	handle.mouse_filter = Control.MOUSE_FILTER_STOP
-	handle.gui_input.connect(func(ev: InputEvent): _on_handle_input(win, ev))
+	var handles := _find_drag_handles(win)
+	for handle in handles:
+		if handle == null or handle.has_meta("_drag_wired"):
+			continue
+		handle.set_meta("_drag_wired", true)
+		handle.mouse_filter = Control.MOUSE_FILTER_STOP
+		handle.gui_input.connect(func(ev: InputEvent): _on_handle_input(win, ev))
 
-func _find_drag_handle(win: Control) -> Control:
-	# 优先 titlebar；否则 board_with_titlebar 的顶部条；否则整个 window 根
+func _find_drag_handles(win: Control) -> Array[Control]:
+	var list: Array[Control] = []
 	for n in win.find_children("*", "", true, false):
 		if n is Control and (n.get_meta("is_titlebar", false) or n.get_meta("titlebar_h", 0) > 0):
-			return n
-	return win
+			list.append(n as Control)
+	if list.is_empty():
+		list.append(win)
+	return list
 
 func _on_handle_input(win: Control, ev: InputEvent) -> void:
 	if ev is InputEventMouseButton and ev.button_index == MOUSE_BUTTON_LEFT: