fix(shim): 优化配置解析、跨平台编码与 UAC 提权逻辑

- 使用 `OsString`/`PathBuf` 替代 `String`，实现跨平台无损编码与命令行参数透传
- 完善 `FromLua` 转换与边界校验，拦截空洞 (`nil`) 及非整数键
- 修复环境变量拼接时由于内置分隔符导致的 `join_paths` 报错
- 优化 Windows 下 UAC 提权执行逻辑，改用宽字符 API (`ShellExecuteExW`)

src/runtime.rs

@@ -1,6 +1,7 @@
 use crate::error::ShimError;
 use crate::{ShimConfig, ShimLayout};
 use mlua::{FromLua, Lua, StdLib, Table, Value};
+use std::ffi::OsStr;
 use std::path::Path;
 use std::{env, fs};
 /// 将 Path 转换为适合 Lua 使用的安全字符串路径
@@ -36,9 +37,36 @@ impl LuaRuntime {
             .map_err(|e| ShimError::Environment(e.to_string()))?;
 
         // 2. 安全暴露 get_env 供配置读取环境变量
+        //    返回按平台路径分隔符拆分后的段数组（自动剥离引号包裹），
+        //    便于 PATH 等列表变量直接嵌入数组：PATH = { prefix, get_env("PATH") }
         let get_env = lua
-            .create_function(|_, key: String| -> mlua::Result<String> {
-                Ok(env::var(key).unwrap_or_default())
+            .create_function(|lua, key: String| -> mlua::Result<Table> {
+                // 缺失变量视为空字符串，拆分后得到空表（不贡献任何路径段）
+                let value = env::var_os(key).unwrap_or_default();
+                // 空输入返回空表；否则按平台分隔符拆分（split_paths 会剥离引号包裹）
+                if value.is_empty() {
+                    return lua.create_table();
+                }
+                let table = lua.create_table()?;
+                for (i, p) in env::split_paths(&value).enumerate() {
+                    // 3. 跨平台提取原始字节并转为 LuaString，保证 100% 无损
+                    #[cfg(unix)]
+                    let lua_str = {
+                        use std::os::unix::ffi::OsStrExt;
+                        lua.create_string(p.as_os_str().as_bytes())?
+                    };
+
+                    #[cfg(windows)]
+                    let lua_str = {
+                        // Windows 路径是 UTF-16，转成字符串或保持其字节表达
+                        let s = p.to_string_lossy();
+                        lua.create_string(s.as_bytes())?
+                    };
+
+                    table.set(i + 1, lua_str)?;
+                }
+
+                Ok(table)
             })
             .map_err(|e| ShimError::Environment(e.to_string()))?;
 
@@ -96,7 +124,7 @@ impl LuaRuntime {
     /// 执行指定脚本文件，直接返回完整的 Lua Table
     pub fn eval_script<T: FromLua>(&self, path: impl AsRef<Path>) -> Result<T, ShimError> {
         let path = path.as_ref();
-
+        // println!("path {:?}", path);
         let bytes = fs::read(path)?;
         let code = String::from_utf8(bytes).map_err(|e| {
             ShimError::InvalidConfig(format!(
@@ -105,7 +133,7 @@ impl LuaRuntime {
                 e.utf8_error()
             ))
         })?;
-
+        println!("code {:?}", code);
         let chunk_name = format!("@{}", path.display());
 
         self.lua
@@ -159,4 +187,98 @@ mod tests {
             .unwrap();
         assert!(matches!(value, Value::Boolean(true)));
     }
+
+    #[test]
+    fn get_env_returns_split_table() {
+        let runtime = LuaRuntime::new(&test_layout()).unwrap();
+        let value: Value = runtime
+            .lua
+            .load(r#"return get_env("PATH")"#)
+            .eval()
+            .unwrap();
+        let table = match value {
+            Value::Table(t) => t,
+            other => panic!("expected table, got {}", other.type_name()),
+        };
+        assert!(
+            table.raw_len() >= 1,
+            "PATH should have at least one segment"
+        );
+
+        // split_paths 会剥离引号包裹，拆分段不应再含双引号
+        for i in 1..=table.raw_len() {
+            let seg: String = table.raw_get(i).unwrap();
+            assert!(
+                !seg.contains('"'),
+                "segment should not contain quote: {seg:?}"
+            );
+        }
+    }
+
+    #[test]
+    fn get_env_missing_returns_empty_table() {
+        let runtime = LuaRuntime::new(&test_layout()).unwrap();
+        let value: Value = runtime
+            .lua
+            .load(r#"return get_env("RSHIM_TEST_NO_SUCH_VAR_12345")"#)
+            .eval()
+            .unwrap();
+        match value {
+            Value::Table(t) => assert_eq!(t.raw_len(), 0),
+            other => panic!("expected table, got {}", other.type_name()),
+        }
+    }
+
+    #[test]
+    fn path_with_get_env_joins_without_quote_error() {
+        // 复现用户场景：PATH = { base_dir .. "/tools/numa", get_env("PATH") }
+        // 宿主 PATH 即使含双引号，也应拆分后正常拼接，而不是报错
+        let runtime = LuaRuntime::new(&test_layout()).unwrap();
+        let cfg: ShimConfig = runtime
+            .lua
+            .load(
+                r#"
+                return {
+                    target = __SHIM_DIR__ .. "/tools/numa/numa.exe",
+                    args = { "--help" },
+                    env = {
+                        PATH = { __SHIM_DIR__ .. "/tools/numa", get_env("PATH") }
+                    }
+                }
+                "#,
+            )
+            .eval()
+            .unwrap();
+
+        let path = cfg.env.get("PATH").unwrap().to_str().unwrap();
+        let prefix = std::env::temp_dir()
+            .join("rshim-test-layout")
+            .to_string_lossy()
+            .replace('\\', "/")
+            + "/tools/numa;";
+        assert!(path.starts_with(&prefix), "unexpected PATH: {path}");
+
+        // 宿主 PATH 的段应被附加在配置前缀之后
+        let host = std::env::var("PATH").unwrap_or_default();
+        if !host.is_empty() {
+            let host_first = std::env::split_paths(&host)
+                .next()
+                .unwrap()
+                .to_string_lossy()
+                .into_owned();
+            assert!(
+                path.contains(&host_first),
+                "missing host PATH segment: {host_first}"
+            );
+        }
+
+        // 宿主 PATH 里引号包裹的畸形段（如 "D:\\...\\bin;"）应被原样保留，
+        // 而不是让整个配置加载失败
+        if host.contains('"') {
+            assert!(
+                path.contains('"'),
+                "quoted host segments should be preserved"
+            );
+        }
+    }
 }