feat(env): 支持环境变量数组跨平台自动拼接

- 支持在 Lua 中配置数组格式的环境变量（如 PATH），由 Rust 按 OS 自动使用 `;` 或 `:` 拼接
- 保持普通字符串格式环境变量的直接覆盖逻辑
- 新增 `ShimConfig::to_command()` 用于快速创建 Command 对象
- 新增 error.rs 明确错误类型
- 新增 build.rs 优化编译

Cargo.lock

@@ -201,6 +201,7 @@ version = "0.1.0"
 dependencies = [
  "fs-err",
  "mlua",
+ "thiserror",
  "unicode-bom",
  "winapi",
 ]
@@ -260,6 +261,26 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "thiserror"
+version = "2.0.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ec86235f5fcc2a73650310756d2ac5b138a5780bbbdfae3eeccec992c435ba4f"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "2.0.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bc04cd3e1236dd4a98afca4569f2deb3f120e5422a4023be2cb683f8486292af"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "unicode-bom"
 version = "2.0.3"