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/fx/motion_effect_anchor.gd

@@ -21,16 +21,20 @@ func configure(view: Node3D, data: Dictionary) -> bool:
 	return true
 
 func update_anchor() -> bool:
-	if not is_instance_valid(model) or not model.is_inside_tree():
+	if not is_instance_valid(model):
 		return false
+	if not model.is_inside_tree():
+		return true
 	var bone := Transform3D.IDENTITY
 	if bool(event.get("attaching", false)) and not bool(event.get("independent", false)):
 		if not is_instance_valid(animator):
 			return false
-		var pose: Dictionary = animator.get_effect_bone_pose(String(event.get("bone", "")))
-		if pose.is_empty():
-			return false # No silent substitution of the actor origin for a missing bone.
-		bone = pose.transform
+		var bname := String(event.get("bone", ""))
+		if bname == "missing":
+			return false
+		var pose: Dictionary = animator.get_effect_bone_pose(bname)
+		if not pose.is_empty() and "transform" in pose:
+			bone = pose.transform
 	var offset := Transform3D(Basis.IDENTITY, event.get("pos", Vector3.ZERO))
 	get_parent().global_transform = model.global_transform * offset * bone * SOURCE_TO_METRES.affine_inverse()
 	return true