Metin2 game client (P0–P11) + mobile asset pipeline

Networked client on the existing Godot 4.7 + libgr2 renderer:
- net: m2dev wire protocol (libsodium KX + XChaCha20), auth/select/game
  phases, EntityStore world model, ~all GC/CG headers. char create/delete,
  private shop / mall / cube, SHOP_GC_START_EX, guild, party (+ CG_PARTY_SET_STATE),
  quests, dragon soul, refine, safebox, exchange.
- UI: in-game windows migrated 1:1 from the reference uiscript/root .py —
  char status (/stat), inventory+equipment, select-item ([SELECT_ITEM] quest
  token), system-option + game-option + ESC system menu, private-shop 39-grid,
  party info board, shop tabs, atlas, minimap, quickbar, chat, …
- EterGrnLib polish: GR2 material blend/two-sided, LOD crossfade, motion-event
  dispatch, contact shadow, ray-AABB picking, weapon grip pre-transform.

Portable asset IO (A1) — all extension/libgr2/formats/mtproto reads routed
through godot::FileAccess (res:// PCK works on iOS/Android); standalone-lib
*_path() kept for the non-Godot CTests. AssetResolver + PropertyRegistry
switched to a baked index (bake_asset_index.gd) instead of std::filesystem.

Mobile builds: build-{android,ios}.sh, export-android.sh, pack-assets.sh,
gen-debug-keystore.sh. Assets ship as a zip mounted at runtime by
project/asset_pack.gd (adb push now; HTTP download is a drop-in later).

ctest 10/10, 34 GDScript suites, macOS/iOS/Android all build.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013EJxkHiNKS4kybHS3XKyAJ

project/fx/skill_fx.gd

@@ -0,0 +1,74 @@
+# SkillFx (P6 收尾) —— 技能 id / 内建特效 id → .mse 文件，接 P5 EffectRegistry。
+#
+#   var sfx := preload("res://fx/skill_fx.gd").new()
+#   sfx.setup(effect_registry, skill_table)
+#   sfx.spawn_skill(1, 3, caster_node)        # 技能 1(samyeon) grade→_4 挂 caster 播
+#   sfx.spawn_special(19, node)               # GC_SPECIAL_EFFECT type 19 = SE_AUTO_HPUP -> drugup_red
+#
+# 技能特效表：skilldesc 的 motion_name（col13）就是特效基名；等级后缀 = 2 + master_type（夹 2..4）。
+#   effect/pc/<class>/effect/<motion>_<N>.mse（EffectRegistry 的 basename 扫描能找到散包 / PC / season1）
+# 少数技能有 _blow / _head / _foot / _yong 子特效；这里只放主特效，缺就跳过。
+extends RefCounted
+
+# GC_SPECIAL_EFFECT 的 type（ItemData.h / Packet.h 的 SE_* enum，值 = 下标）-> etc 特效基名。
+# 不全 —— 只填常见的（真机 GM 号狂刷 19/20 自动喝药）。
+const SPECIAL_FX := {
+	1: "drugup_red",       # SE_HPUP_RED
+	2: "drugup_blue",      # SE_SPUP_BLUE
+	3: "drugup_green",     # SE_SPEEDUP_GREEN
+	4: "drugup_purple",    # SE_DXUP_PURPLE
+	9: "firecracker_1",    # SE_CHINA_FIREWORK
+	11: "firecracker_2",   # SE_SUCCESS（凑合）
+	12: "fail",            # SE_FAIL
+	19: "drugup_red",      # SE_AUTO_HPUP
+	20: "drugup_blue",     # SE_AUTO_SPUP
+}
+
+var fxr: RefCounted          # EffectRegistry
+var table: RefCounted        # SkillTable
+# 一个 motion 常见的子特效后缀（有就一起播）
+const SUB_SUFFIX := ["", "_blow", "_hand", "_head", "_foot", "_yong"]
+
+func setup(effect_registry: RefCounted, skill_table: RefCounted) -> void:
+	fxr = effect_registry
+	table = skill_table
+
+# skill_id + master_type(0..3) -> 主特效基名（<motion>_<N>）。查不到 motion 返回 ""。
+func skill_effect_name(skill_id: int, master: int = 0) -> String:
+	if table == null:
+		return ""
+	var mn := String(table.entry(skill_id).get("motion", ""))
+	if mn == "":
+		return ""
+	var n := clampi(2 + master, 2, 4)
+	return "%s_%d" % [mn, n]
+
+# 在 host 下播技能特效（主 + 已存在的子特效各一份）。返回播了几个。
+func spawn_skill(skill_id: int, master: int, host: Node3D) -> int:
+	if fxr == null or host == null:
+		return 0
+	var base := skill_effect_name(skill_id, master)
+	if base == "":
+		return 0
+	var parts := base.rsplit("_", false, 1)   # "samyeon_4" -> ["samyeon", "4"]
+	var stem: String = parts[0]
+	var num: String = parts[1] if parts.size() > 1 else ""
+	var played := 0
+	for suf in SUB_SUFFIX:
+		var name: String = base
+		if suf != "":
+			name = "%s%s_%s" % [stem, suf, num] if num != "" else stem + suf
+		if fxr.resolve(name) != "":
+			fxr.spawn(name, host, true)
+			played += 1
+	return played
+
+# GC_SPECIAL_EFFECT type -> 内建特效。返回是否播了。
+func spawn_special(special_id: int, host: Node3D) -> bool:
+	if fxr == null or host == null or not SPECIAL_FX.has(special_id):
+		return false
+	var name: String = SPECIAL_FX[special_id]
+	if fxr.resolve(name) == "":
+		return false
+	fxr.spawn(name, host, true)
+	return true