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

formats/msa.h

@@ -0,0 +1,31 @@
+// .msa —— Metin2 动作描述（文本，ScriptType MotionData）。M2 T1。
+#pragma once
+#include <string>
+#include <vector>
+
+namespace fmt {
+
+struct MotionEvent {
+    int         type = 0;          // MotionEventType（10=effect, 4/5=sound, ...）
+    float       start_time = 0;    // StartingTime
+    std::string effect_file;       // EffectFileName（type 10）
+    std::string sound_file;        // SoundFileName
+    float       position[3] = {0, 0, 0};
+};
+
+struct Msa {
+    std::string motion_gr2;               // MotionFileName（原样，含 d:\... 前缀）
+    float       duration = 0;             // MotionDuration
+    float       accumulation[3] = {0,0,0};// Accumulation（root motion 位移）
+    std::vector<MotionEvent> events;
+	bool        has_loop_data = false;    // LoopData 是片段循环，不等同于整段播放模式
+	int         motion_loop_count = 0;    // -1 无限；原客户端仅在 >1 或 -1 时回绕片段
+	bool        loop_cancel_enable = false;
+	float       loop_start_time = 0;
+	float       loop_end_time = 0;
+};
+
+bool parse_msa(const std::string& text, Msa& out, std::string* err);
+bool parse_msa_file(const std::string& path, Msa& out, std::string* err);
+
+} // namespace fmt