This is a comment left during a code review.
Path: scripts/ui.js
Line: 99-115

Comment:
**`assertSafeWindowsShellArgs` no longer called before cmd.exe command line construction**

The old `createSpawnOptions` called `assertSafeWindowsShellArgs(args)` when `shouldUseShellForCommand` returned `true` (which it did for any `.cmd`/`.bat`/`.com` file). The new `normalizeWindowsCommand` function builds a cmd.exe `/c` command line by simply joining args with spaces — but never validates those args against the `WINDOWS_UNSAFE_SHELL_ARG_PATTERN`.

Because `run()` passes `["install", ...rest]` or `["run", script, ...rest]` where `rest` comes directly from `process.argv`, a user-supplied argument containing `&`, `|`, `<`, `>`, `^`, `%`, or `!` will be interpreted as cmd.exe metacharacters when executed:

```
node scripts/ui.js dev "myarg & evil-command"
```

…would produce `commandLine = '"C:\\...\\pnpm.CMD" myarg & evil-command'` which cmd.exe would split at `&` and execute both parts.

`assertSafeWindowsShellArgs` should be called before joining args into the command line string:

```js
function normalizeWindowsCommand(cmd, args) {
  if (process.platform !== "win32") {
    return { command: cmd, commandArgs: args };
  }
  const extension = path.extname(cmd).toLowerCase();
  if (!WINDOWS_SHELL_EXTENSIONS.has(extension)) {
    return { command: cmd, commandArgs: args };
  }

  assertSafeWindowsShellArgs(args); // add this validation

  const hasPathSeparator = cmd.includes("\\") || cmd.includes("/");
  const quotedCmd = hasPathSeparator ? `"${cmd}"` : cmd;
  const commandLine = args.length > 0 ? `${quotedCmd} ${args.join(" ")}` : quotedCmd;

  const command = process.env.comspec || "cmd.exe";
  const commandArgs = ["/d", "/s", "/c", commandLine];
  return { command, commandArgs };
}
```

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: 302-310

Comment:
**TextDecoder not flushed on stream close**

`TextDecoder` instances created with `{ stream: true }` maintain an internal buffer for incomplete multi-byte sequences that span chunk boundaries. That buffer is never flushed — there is no final call to `decoder.decode(new Uint8Array(0))` (i.e., without `stream: true`) after the last data event.

For GBK/GB18030 output, if the last data event ends on the first byte of a two-byte character, that byte will silently be dropped. The `close` handler should flush both decoders and append any remaining bytes to `stdout`/`stderr`:

```js
child.on("close", (code, signal) => {
  if (settled) return;
  // flush any buffered multi-byte tail
  if (stdoutDecoder) stdout += stdoutDecoder.decode();
  if (stderrDecoder) stderr += stderrDecoder.decode();
  settled = true;
  // …rest of existing close handler…
```

The same pattern applies to the `onStdout`/`onStderr` handlers in `src/process/supervisor/adapters/child.ts` (lines 114–132) — a corresponding flush should be added when the `child` emits `close`.

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