refactor: 配置文件引擎迁移至 mlua 并优化环境变量注入

- 配置文件解析引擎由 shim 替换为 mlua (Lua 5.4)
- 优化路由策略：统一以根目录 shims.lua 为入口，支持 tools/ 目录模块化降级探测
- 自动注入 __SHIM_DIR__ 绝对路径与 package.path 模块搜索路径
- 环境变量改用 Command::envs 安全注入，并在 UAC 提权时透传

Cargo.toml

@@ -2,7 +2,7 @@
 name = "rshim"
 version = "0.1.0"
 authors = ["anonymous <anonymous@example.com>"]
-edition = "2018"
+edition = "2024"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
@@ -11,12 +11,10 @@ edition = "2018"
 opt-level = "z"
 panic = "abort"
 [dependencies]
-fs-err = "2.5.0"
-unicode-bom = "1"
-
-[dependencies.winapi]
-version = "0.3"
-features = [
+fs-err = "3.3.1"
+unicode-bom = "2.0.3"
+mlua = { version = "0.12.0", features = ["lua54", "vendored"] }
+winapi = { version = "0.3", features = [
     "wincon",
     "consoleapi",
     "minwindef",
@@ -28,4 +26,6 @@ features = [
     "processthreadsapi",
     "objbase",
     "impl-default"
-]
+] }
+
+