[codex] Centralize subprocess env boundaries (#585)

* Centralize subprocess env boundaries

* Remove env boundary static audit test

* Tighten env boundary process launches

* Fix Windows native process launches

* Inline provider env pass-throughs

packages/server/src/utils/windows-command.ts

@@ -0,0 +1,42 @@
+import { extname } from "node:path";
+
+export function isWindowsCommandScript(executablePath: string): boolean {
+  const extension = extname(executablePath).toLowerCase();
+  return process.platform === "win32" && (extension === ".cmd" || extension === ".bat");
+}
+
+function escapeWindowsCmdValue(value: string): string {
+  if (process.platform !== "win32") return value;
+
+  const isQuoted = value.startsWith('"') && value.endsWith('"');
+  const unquoted = isQuoted ? value.slice(1, -1) : value;
+  const escaped = unquoted.replace(/%/g, "%%").replace(/([&|^<>()!])/g, "^$1");
+
+  if (isQuoted || /[\s"]/u.test(unquoted)) {
+    const quoted = escaped
+      .replace(/(\\*)"/g, (_match, slashes: string) => `${slashes}${slashes}\\"`)
+      .replace(/\\+$/u, (slashes) => `${slashes}${slashes}`);
+    return `"${quoted}"`;
+  }
+
+  return escaped;
+}
+
+/**
+ * When spawning with `shell: true` on Windows, the command is passed to
+ * `cmd.exe /d /s /c "command args"`. The `/s` strips outer quotes, so a
+ * command path with spaces (e.g. `C:\Program Files\...`) is split at the
+ * space. Wrapping it in quotes produces the correct `"C:\Program Files\..." args`.
+ */
+export function quoteWindowsCommand(command: string): string {
+  return escapeWindowsCmdValue(command);
+}
+
+/**
+ * `spawn(..., { shell: true })` on Windows also passes argv through `cmd.exe`.
+ * Any argument containing spaces must be quoted or it will be split before the
+ * child process sees it.
+ */
+export function quoteWindowsArgument(argument: string): string {
+  return escapeWindowsCmdValue(argument);
+}