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/loslib.c

@@ -20,6 +20,7 @@
 
 #include "lauxlib.h"
 #include "lualib.h"
+#include "llimits.h"
 
 
 /*
@@ -33,7 +34,7 @@
 #if defined(LUA_USE_WINDOWS)
 #define LUA_STRFTIMEOPTIONS  "aAbBcdHIjmMpSUwWxXyYzZ%" \
     "||" "#c#x#d#H#I#j#m#M#S#U#w#W#y#Y"  /* two-char options */
-#elif defined(LUA_USE_C89)  /* ANSI C 89 (only 1-char options) */
+#elif defined(LUA_USE_C89)  /* C89 (only 1-char options) */
 #define LUA_STRFTIMEOPTIONS  "aAbBcdHIjmMpSUwWxXyYZ%"
 #else  /* C99 specification */
 #define LUA_STRFTIMEOPTIONS  "aAbBcCdDeFgGhHIjmMnprRStTuUVwWxXyYzZ%" \
@@ -272,9 +273,9 @@ static int getfield (lua_State *L, const char *key, int d, int delta) {
 
 
 static const char *checkoption (lua_State *L, const char *conv,
-                                ptrdiff_t convlen, char *buff) {
+                                size_t convlen, char *buff) {
   const char *option = LUA_STRFTIMEOPTIONS;
-  int oplen = 1;  /* length of options being checked */
+  unsigned oplen = 1;  /* length of options being checked */
   for (; *option != '\0' && oplen <= convlen; option += oplen) {
     if (*option == '|')  /* next block? */
       oplen++;  /* will check options with next length (+1) */
@@ -332,7 +333,8 @@ static int os_date (lua_State *L) {
         size_t reslen;
         char *buff = luaL_prepbuffsize(&b, SIZETIMEFMT);
         s++;  /* skip '%' */
-        s = checkoption(L, s, se - s, cc + 1);  /* copy specifier to 'cc' */
+        /* copy specifier to 'cc' */
+        s = checkoption(L, s, ct_diff2sz(se - s), cc + 1);
         reslen = strftime(buff, SIZETIMEFMT, cc, stm);
         luaL_addsize(&b, reslen);
       }