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/system_setting_system.gd

@@ -0,0 +1,147 @@
+# system_setting_system.gd —— Metin2 40250 音频视听与战斗选项系统 1:1
+# 对照 40250 服务端与客户端 PythonSystem.cpp, uisystemoption.py, uigameoption.py
+class_name SystemSettingSystem
+extends RefCounted
+
+signal setting_changed(setting_name: String, new_val: Variant)
+signal pk_mode_changed(new_mode: int, mode_name: String)
+
+enum PkMode {
+	PEACE = 0,   # 和平
+	REVENGE = 1, # 善恶 (仅可攻击负善恶红名)
+	GUILD = 2,   # 阵营 (公会战保护)
+	FREE = 3     # 自由 (无限制)
+}
+
+# 音频设置
+var bgm_volume: float = 0.8:
+	set(v):
+		bgm_volume = clampf(v, 0.0, 1.0)
+		setting_changed.emit("bgm_volume", bgm_volume)
+
+var sfx_volume: float = 0.8:
+	set(v):
+		sfx_volume = clampf(v, 0.0, 1.0)
+		setting_changed.emit("sfx_volume", sfx_volume)
+
+var is_muted: bool = false:
+	set(v):
+		is_muted = v
+		setting_changed.emit("is_muted", is_muted)
+
+# 视距与画质设置
+var camera_distance: float = 25.0:
+	set(v):
+		camera_distance = clampf(v, 15.0, 40.0)
+		setting_changed.emit("camera_distance", camera_distance)
+
+var fog_level: int = 1: # 0: 无, 1: 近, 2: 远
+	set(v):
+		fog_level = clampi(v, 0, 2)
+		setting_changed.emit("fog_level", fog_level)
+
+var shadow_quality: int = 1: # 0: 关, 1: 地面, 2: 全部
+	set(v):
+		shadow_quality = clampi(v, 0, 2)
+		setting_changed.emit("shadow_quality", shadow_quality)
+
+# 战斗飘字与标签显示
+var show_damage_dealt: bool = true
+var show_damage_received: bool = true
+var show_critical_hit: bool = true
+var show_monster_names: bool = true
+var show_player_names: bool = true
+
+# PK 模式
+var current_pk_mode: int = PkMode.PEACE
+
+# 设置 PK 模式
+func set_pk_mode(mode: int) -> Dictionary:
+	if mode < PkMode.PEACE or mode > PkMode.FREE:
+		return {"ok": false, "reason": "INVALID_PK_MODE", "msg": "无效的 PK 模式！"}
+
+	current_pk_mode = mode
+	var mname := get_pk_mode_name(mode)
+	pk_mode_changed.emit(mode, mname)
+
+	return {
+		"ok": true,
+		"mode": mode,
+		"mode_name": mname,
+		"msg": "PK 模式已切换为【%s】！" % mname
+	}
+
+# 获取模式中文名称
+func get_pk_mode_name(mode: int) -> String:
+	match mode:
+		PkMode.PEACE: return "和平模式"
+		PkMode.REVENGE: return "善恶反击模式"
+		PkMode.GUILD: return "阵营公会模式"
+		PkMode.FREE: return "自由对决模式"
+		_: return "未知模式"
+
+# 判定是否可以对指定目标发起攻击 (PK 判定状态机)
+func can_attack_target(
+	target_is_player: bool,
+	target_alignment: int = 0,
+	target_guild_id: int = 0,
+	my_guild_id: int = 0
+) -> bool:
+	# 怪物/NPC 永远可以攻击
+	if not target_is_player:
+		return true
+
+	# 玩家间攻击依据 PK 模式判定
+	match current_pk_mode:
+		PkMode.PEACE:
+			# 和平模式：严禁攻击任何玩家
+			return false
+
+		PkMode.REVENGE:
+			# 善恶模式：只可攻击红名玩家 (善恶值 < 0)
+			return target_alignment < 0
+
+		PkMode.GUILD:
+			# 阵营模式：同公会玩家受到保护，禁止攻击
+			if my_guild_id > 0 and target_guild_id > 0 and my_guild_id == target_guild_id:
+				return false
+			return true
+
+		PkMode.FREE:
+			# 自由模式：可攻击任何玩家
+			return true
+
+		_:
+			return false
+
+# 导出配置项
+func export_settings() -> Dictionary:
+	return {
+		"bgm_volume": bgm_volume,
+		"sfx_volume": sfx_volume,
+		"is_muted": is_muted,
+		"camera_distance": camera_distance,
+		"fog_level": fog_level,
+		"shadow_quality": shadow_quality,
+		"show_damage_dealt": show_damage_dealt,
+		"show_damage_received": show_damage_received,
+		"show_critical_hit": show_critical_hit,
+		"show_monster_names": show_monster_names,
+		"show_player_names": show_player_names,
+		"current_pk_mode": current_pk_mode
+	}
+
+# 导入配置项
+func import_settings(cfg: Dictionary) -> void:
+	if cfg.has("bgm_volume"): bgm_volume = float(cfg["bgm_volume"])
+	if cfg.has("sfx_volume"): sfx_volume = float(cfg["sfx_volume"])
+	if cfg.has("is_muted"): is_muted = bool(cfg["is_muted"])
+	if cfg.has("camera_distance"): camera_distance = float(cfg["camera_distance"])
+	if cfg.has("fog_level"): fog_level = int(cfg["fog_level"])
+	if cfg.has("shadow_quality"): shadow_quality = int(cfg["shadow_quality"])
+	if cfg.has("show_damage_dealt"): show_damage_dealt = bool(cfg["show_damage_dealt"])
+	if cfg.has("show_damage_received"): show_damage_received = bool(cfg["show_damage_received"])
+	if cfg.has("show_critical_hit"): show_critical_hit = bool(cfg["show_critical_hit"])
+	if cfg.has("show_monster_names"): show_monster_names = bool(cfg["show_monster_names"])
+	if cfg.has("show_player_names"): show_player_names = bool(cfg["show_player_names"])
+	if cfg.has("current_pk_mode"): set_pk_mode(int(cfg["current_pk_mode"]))