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/spt.cpp

@@ -0,0 +1,100 @@
+#include "spt.h"
+
+#include "m2_tokvec.h" // read_file
+
+#include <cctype>
+#include <cstdint>
+#include <cstring>
+
+namespace fmt {
+
+namespace {
+
+bool ends_with_ci(const std::string& s, const char* suf) {
+    size_t n = std::strlen(suf);
+    if (s.size() < n) return false;
+    for (size_t i = 0; i < n; ++i)
+        if (std::tolower((unsigned char)s[s.size() - n + i]) != std::tolower((unsigned char)suf[i]))
+            return false;
+    return true;
+}
+
+std::string token_ci(const std::string& bytes, const char* needle) {
+    const size_t n = std::strlen(needle);
+    if (n == 0 || bytes.size() < n) return "";
+    for (size_t i = 0; i + n <= bytes.size(); ++i) {
+        bool match = true;
+        for (size_t j = 0; j < n; ++j) {
+            if (std::tolower((unsigned char)bytes[i + j]) !=
+                    std::tolower((unsigned char)needle[j])) {
+                match = false;
+                break;
+            }
+        }
+        if (!match) continue;
+        size_t e = i + n;
+        while (e < bytes.size()) {
+            const unsigned char c = (unsigned char)bytes[e];
+            if (!(std::isalnum(c) || c == '_' || c == '-')) break;
+            ++e;
+        }
+        return bytes.substr(i, e - i);
+    }
+    return "";
+}
+
+std::string as_dds(std::string s) {
+    if (s.empty()) return s;
+    const size_t dot = s.find_last_of('.');
+    if (dot != std::string::npos) s.resize(dot);
+    return s + ".dds";
+}
+
+} // namespace
+
+bool sniff_spt(const std::string& b, SptInfo& out) {
+    out = SptInfo{};
+    if (b.size() < 20) return false;
+
+    std::memcpy(&out.header_dword, b.data(), 4);
+    uint32_t maglen = 0;
+    std::memcpy(&maglen, b.data() + 4, 4);
+    if (maglen >= 4 && maglen <= 32 && 8 + maglen <= b.size()) {
+        out.magic.assign(b.data() + 8, b.data() + 8 + maglen);
+        // 去掉可能的尾随 NUL
+        while (!out.magic.empty() && out.magic.back() == '\0') out.magic.pop_back();
+    }
+    out.ok = out.magic.rfind("__IdvSpt", 0) == 0;
+
+    // 扫描可打印 ASCII 段，收 .tga / .dds 结尾的
+    std::string cur;
+    auto flush = [&] {
+        if (cur.size() >= 5 && (ends_with_ci(cur, ".tga") || ends_with_ci(cur, ".dds"))) {
+            // 只留文件名基础部分之后的路径（原样）
+            out.texture_refs.push_back(cur);
+        }
+        cur.clear();
+    };
+    for (unsigned char c : b) {
+        if (c >= 0x20 && c < 0x7F) {
+            cur += (char)c;
+        } else {
+            flush();
+        }
+    }
+    flush();
+
+    // 这两个名字在真实 v2 .spt 中常紧跟二进制标记，不会由上面的
+    // "字符串必须正好以扩展名结尾" 规则捕获。
+    out.composite_texture = as_dds(token_ci(b, "CompositeMap"));
+    out.self_shadow_texture = as_dds(token_ci(b, "CompositeShadowMap"));
+    return out.ok;
+}
+
+bool sniff_spt_file(const std::string& path, SptInfo& out) {
+    std::string b;
+    if (!read_file(path, b)) return false;
+    return sniff_spt(b, out);
+}
+
+} // namespace fmt