This is a comment left during a code review.
Path: src/process/exec.ts
Line: 109-112

Comment:
**`"gbk"` is not a valid Node.js `BufferEncoding`**

`BufferEncoding` is defined as `"ascii" | "utf8" | "utf-8" | "utf16le" | "ucs2" | "ucs-2" | "base64" | "base64url" | "latin1" | "binary" | "hex"`. The string `"gbk"` is not in that union, so this code will:

1. **Fail TypeScript compilation** — `Type '"gbk"' is not assignable to type 'BufferEncoding'`.
2. **Fail at runtime** — `execFile` passes the encoding value directly to `Buffer.toString()`, which does not understand `"gbk"` and will throw `ERR_UNKNOWN_ENCODING` (or produce garbage in some Node versions).

The correct approach is to request a raw `Buffer` from `execFile` (by omitting / nulling the encoding) and then decode it with the WHATWG `TextDecoder`, which _does_ support GBK natively in Node ≥ 18:

```typescript
// Build exec options without an encoding so we get Buffer output
const execOptions =
  typeof opts === "number"
    ? { timeout: opts }
    : { timeout: opts.timeoutMs, maxBuffer: opts.maxBuffer, cwd: opts.cwd };

// Determine the decoder to use for stdout/stderr
const isWindows = process.platform === "win32";
const charsetLabel =
  typeof opts === "object" && opts.encoding
    ? opts.encoding
    : isWindows
      ? "gbk"        // CP936 – the default code-page for cmd.exe
      : "utf-8";

const decoder = new TextDecoder(charsetLabel);    // TextDecoder accepts "gbk" natively

const raw = await execFileAsync(execCommand, execArgs, { ...execOptions, encoding: null });
return {
  stdout: decoder.decode(raw.stdout as Buffer),
  stderr: decoder.decode(raw.stderr as Buffer),
};
```

You will also need to adjust the `encoding` field in `opts` from `BufferEncoding` to `string` (or at least a wider alias union) so callers can pass `"gbk"`, `"big5"`, etc.

How can I resolve this? If you propose a fix, please make it concise.

---

This is a comment left during a code review.
Path: src/process/exec.ts
Line: 105

Comment:
**`encoding` option type too narrow for GBK**

The `encoding` option is typed as `BufferEncoding`, which does not include `"gbk"`. Callers who try to pass `encoding: "gbk"` explicitly will get a compile error. The type should be widened to accept any WHATWG-compatible label string (or at minimum a dedicated alias union):

```suggestion
    | { timeoutMs?: number; maxBuffer?: number; cwd?: string; encoding?: string } = 10_000,
```

Once the `execFile` call is switched to `encoding: null` + `TextDecoder` (see adjacent comment), `encoding` here becomes the label passed to `new TextDecoder(label)` rather than a `BufferEncoding`, so `string` is the appropriate type.

How can I resolve this? If you propose a fix, please make it concise.