feat: 适配 Lua 5.5.1 最新版 (lua_5.5.1 分支)

- lib/lua 替换为 Lua 5.5.1 官方源码(2026-07 发布, 当前最新)
- luaconf.h LUA_EXTRASPACE 扩为 272 字节(与 5.4.8 同方案)
- C API 完全兼容, 桥接层零改动
- PackagePathConfig 测试沿用跨版本语义断言(5.4+ require 返回 loader data 路径)
- 验证: GTest 44/44 通过

lib/lua/lzio.h

@@ -32,7 +32,7 @@ typedef struct Mbuffer {
 #define luaZ_sizebuffer(buff)	((buff)->buffsize)
 #define luaZ_bufflen(buff)	((buff)->n)
 
-#define luaZ_buffremove(buff,i)	((buff)->n -= (i))
+#define luaZ_buffremove(buff,i)	((buff)->n -= cast_sizet(i))
 #define luaZ_resetbuffer(buff) ((buff)->n = 0)
 
 
@@ -48,6 +48,7 @@ LUAI_FUNC void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader,
                                         void *data);
 LUAI_FUNC size_t luaZ_read (ZIO* z, void *b, size_t n);	/* read next n bytes */
 
+LUAI_FUNC const void *luaZ_getaddr (ZIO* z, size_t n);
 
 
 /* --------- Private Part ------------------ */