feat: 适配 Lua 5.2.4 (lua_5.2.4 分支)

- lib/lua 替换为 Lua 5.2.4 官方源码; CMakeLists 补 lbitlib.c(5.2 linit 注册 bit32)、删 lutf8lib.c(5.2 无此文件)
- I/O 重定向机制改造: 5.2 无 lua_getextraspace → iopath 指针存入
  Registry 固定索引(IOPATH_REG_IDX=1), 回调经 get_iopath() 取回,
  free_lua 时释放 —— 该方案同样适用于更低版本
- typed interop 版本自适应: capture_result() 的 lua_isinteger 分支用
  #if LUA_VERSION_NUM >= 503 包裹, 5.2 及以下所有数字统一 CJT_NUM
- 测试跨版本适配: PackagePathConfig 接受 require 的两种返回语义;
  typed 数值断言 EXPECT_INT_OR_NUM 宏兼容有无 integer 子类型;
  大整数保真断言仅对 5.3+ 生效(5.2 经 double 必然丢精度)
- 验证: GTest 44/44 通过

lib/lua_cj_api.cpp

@@ -1,4 +1,9 @@
 #include "lua_cj_api.h"
+#include <new>
+
+// Lua 5.2/5.1 无 lua_getextraspace，改用 Registry 固定索引存储 iopath 指针
+#define IOPATH_REG_IDX  1
+
 extern "C"
 {
     #include <string.h>
@@ -351,15 +356,36 @@ int cleanup(void *selfd)
 int free_lua(void *selfd)
 {
     lua_runner* self = (lua_runner*)selfd;
+    // 释放 Registry 中的 iopath（若存在）
+    Lua_runner *runner = (Lua_runner*)self->lua_obj;
+    if (runner != NULL) {
+        lua_State *L = runner->get_lua_State();
+        if (L != NULL) {
+            lua_rawgeti(L, LUA_REGISTRYINDEX, IOPATH_REG_IDX);
+            iopath *p = (iopath*)lua_touserdata(L, -1);
+            lua_pop(L, 1);
+            delete p;  // NULL 也安全
+        }
+    }
     delete((Lua_runner*)self->lua_obj);
     free(self);
     return 0;
 }
 
 /*-------------重定向io操作------------------------*/
+/* Lua 5.2/5.1 无 lua_getextraspace，改用 Registry 固定索引存储 iopath 指针 */
+
+static iopath *get_iopath(lua_State *L)
+{
+    lua_rawgeti(L, LUA_REGISTRYINDEX, IOPATH_REG_IDX);
+    iopath *r = (iopath *)lua_touserdata(L, -1);
+    lua_pop(L, 1);
+    return r;
+}
+
 static const char *full_path(lua_State *L, int isOut)
 {
-    iopath *r = (iopath *)lua_getextraspace(L);
+    iopath *r = get_iopath(L);
     static char buf[512];
     snprintf(buf, sizeof(buf), "%s/%s", r->iopath, isOut ? "output" : "input");
     return buf;
@@ -368,7 +394,7 @@ static const char *full_path(lua_State *L, int isOut)
 //劫持读取终端输入，触发回调
 static int l_tty_read(lua_State *L)
 {
-    iopath *r = (iopath *)lua_getextraspace(L);
+    iopath *r = get_iopath(L);
     if (r->funcs.io_input) r->funcs.io_input();
     const char *fname = full_path(L, 0);
     FILE *fp = fopen(fname, "rb");
@@ -394,7 +420,7 @@ static int l_tty_read(lua_State *L)
 //劫持到终端输出，输出结束触发回调
 static int l_tty_write(lua_State *L)
 {
-    iopath *r = (iopath *)lua_getextraspace(L);
+    iopath *r = get_iopath(L);
     const char *fname = full_path(L, 1);
     FILE *fp = fopen(fname, "a");
     if (!fp) return luaL_error(L, "tty write open fail: %s", fname);
@@ -406,7 +432,7 @@ static int l_tty_write(lua_State *L)
     return 0;
 }
 static int l_print(lua_State *L) {
-    iopath *r = (iopath *)lua_getextraspace(L);
+    iopath *r = get_iopath(L);
     const char *fname = full_path(L, 1);  // 输出到 output 文件
     FILE *fp = fopen(fname, "a");
     if (!fp) return luaL_error(L, "print redirect open fail: %s", fname);
@@ -475,7 +501,7 @@ int redirecct_path(lua_State *L)
         errno = LUAERR_LUA_STATE;
         return -1;
     }
-    iopath *p = (iopath*)lua_getextraspace(L);
+    iopath *p = get_iopath(L);
     static const luaL_Reg fake_methods[] = {
         {"read",   l_tty_read},
         {"write",  l_tty_write},
@@ -547,15 +573,16 @@ void *init_lua_runner(const char *pathio,const char *pkgpath,int(*input)(),int(*
         errno = LUAERR_LUA_STATE;
         return NULL;
     }
-    iopath *io_path = (iopath*)lua_getextraspace(L);
-    //申请额外空间
+    // Lua 5.2/5.1 无 extraspace：new 一个 iopath 存入 Registry
+    iopath *io_path = new (std::nothrow) iopath();
     if(pathio == NULL)
     {
+        delete io_path;
         goto WITHOUT_REDIRECT;
     }
     
     if(io_path == NULL){
-        errno = LUAERR_CALLBACK;
+        errno = LUAERR_CLASS_LOST;
         return NULL;
     }
 
@@ -564,6 +591,9 @@ void *init_lua_runner(const char *pathio,const char *pkgpath,int(*input)(),int(*
     io_path->funcs.io_output = output;
     //装载重定向路径
     strcpy(io_path->iopath,pathio);
+    //存入 Registry 固定索引供回调取用
+    lua_pushlightuserdata(L, (void*)io_path);
+    lua_rawseti(L, LUA_REGISTRYINDEX, IOPATH_REG_IDX);
     //注册重定向
     if(redirecct_path(L)==-1){
         errno = LUAERR_LUA_STATE;