chore: import upstream snapshot with attribution

tests/unit/launch-codex-windows-spawn-6312.test.ts

@@ -0,0 +1,20 @@
+import { test } from "node:test";
+import assert from "node:assert/strict";
+
+import { resolveCodexSpawn } from "../../bin/cli/commands/launch-codex.mjs";
+
+// Regression guard for #6312: on Windows the `codex` binary is an npm `.cmd`
+// shim that `spawn` cannot resolve without a shell (bare "codex" → ENOENT).
+test("resolveCodexSpawn: win32 spawns codex.cmd through a shell", () => {
+  const { command, shell } = resolveCodexSpawn("win32");
+  assert.equal(command, "codex.cmd");
+  assert.equal(shell, true);
+});
+
+test("resolveCodexSpawn: non-Windows platforms spawn the bare binary without a shell", () => {
+  for (const platform of ["linux", "darwin", "freebsd"]) {
+    const { command, shell } = resolveCodexSpawn(platform);
+    assert.equal(command, "codex", `${platform} command`);
+    assert.equal(shell, undefined, `${platform} shell`);
+  }
+});