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/terrain_files.h

@@ -0,0 +1,44 @@
+// 区块二进制：height.raw / tile.raw / attr.atr / water.wtr。
+// 真值来源：PRTerrainLib/Terrain.cpp（LoadHeightMap / RAW_LoadTileMap / LoadAttrMap /
+// LoadWaterMapFile）+ Terrain.h / TerrainType.h 常量。SHINSOO §5.3。
+//
+//   XSIZE = 128
+//   height.raw : 无头，u16 LE [131*131]              (HEIGHTMAP_RAW = XSIZE+3)
+//   tile.raw   : 无头，u8    [258*258]               (TILEMAP_RAW   = XSIZE*2+2)
+//   attr.atr   : 6B 头 {u16 magic=2634, u16 w=256, u16 h=256} + u8 [256*256]
+//   water.wtr  : 7B 头 {u16 magic=5426, u16 w=128, u16 h=128, u8 layers}
+//                + u8 [128*128] + layers×(u16 或 u32) 层高
+#pragma once
+#include <cstdint>
+#include <string>
+#include <vector>
+
+namespace fmt {
+
+constexpr int HEIGHTMAP_RAW_XY = 131; // 128+3
+constexpr int TILEMAP_RAW_XY   = 258; // 128*2+2
+constexpr int ATTRMAP_XY       = 256; // 128*2
+constexpr int WATERMAP_XY      = 128;
+constexpr uint16_t ATTR_MAGIC  = 2634;
+constexpr uint16_t WATER_MAGIC = 5426;
+
+struct HeightMap {
+    std::vector<uint16_t> raw; // 131*131, 行主序（含 1 圈边界样本）
+    uint16_t at(int sx, int sy) const { // 与 Terrain.h GetHeight 一致：+1 偏移
+        return raw[(sy + 1) * HEIGHTMAP_RAW_XY + (sx + 1)];
+    }
+};
+struct TileMap  { std::vector<uint8_t> raw; }; // 258*258
+struct AttrMap  { std::vector<uint8_t> data; }; // 256*256（去头）
+struct WaterMap {
+    uint8_t layer_count = 0;
+    std::vector<uint8_t> ids;      // 128*128；0xFF = 无水
+    std::vector<int32_t> heights;  // layer_count 个
+};
+
+bool load_height_map(const std::string& path, HeightMap& out, std::string* err);
+bool load_tile_map(const std::string& path, TileMap& out, std::string* err);
+bool load_attr_map(const std::string& path, AttrMap& out, std::string* err);
+bool load_water_map(const std::string& path, WaterMap& out, std::string* err);
+
+} // namespace fmt