fix: codex login on Windows hit nested quoting hell

Clicking 'codex 认证' on Chinese Windows produced '文件名、目录名或卷
标语法不正确' before codex ever started. The launcher was spawning:

    cmd.exe /c start cmd.exe /k <command-with-quoted-path-and-args>

which forced the argv through four parsers in a row - Node
child_process argv quoting, outer cmd.exe /c, start, and inner
cmd.exe /k - each with different quote escape rules. Node emits
CRT-style '"' for embedded quotes; cmd.exe does not understand
that escape and chopped 'cd /d "C:\...\"' into a literal
backslash plus a broken path. 'cd /d' then rejected the path.

Reduce parsing to a single layer by writing the command to a
temp .bat file (ASCII + CRLF, at a fixed path in $TEMP so
successive logins do not accumulate files) and launching it with
'cmd /c start "" <batPath>'. The quotes inside the bat are now
interpreted once, by the bat's own cmd.exe, exactly as typed.

Also add a unit test that asserts the generated bat content is
ASCII-only with CRLF line endings and contains the right cd /d
and codex invocation - future regressions fail at npm test time
instead of on a real Windows box.

Author: ouyyyyang

core/agent/src/codex-login.ts

@@ -1,4 +1,7 @@
 import { spawn } from "node:child_process";
+import { writeFile } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
 import type { SpawnProcess, SpawnedProcessLike } from "./codex.js";
 
 export interface CodexLoginStatus {
@@ -134,12 +137,26 @@ async function launchCodexLoginOnWindows(input: {
   codexBin: string;
   workspaceRoot: string;
 }): Promise<void> {
-  const command = buildCodexLoginCommandWindows(input);
+  // Why a .bat file instead of 'cmd /c start cmd /k "..."':
+  //
+  // The nested form forced the command line through four parsers in a
+  // row (Node child_process argv quoting -> outer cmd.exe /c -> start ->
+  // inner cmd.exe /k). Each layer uses different quote escaping rules
+  // and cmd.exe in particular chops '\"' into a literal backslash plus
+  // a quote, which mangled the 'cd /d "C:\...\"' prefix and produced
+  // '文件名、目录名或卷标语法不正确' on Chinese Windows before codex
+  // ever started. Writing the command to a .bat file reduces parsing
+  // to a single layer inside the bat's own cmd.exe, where the quotes
+  // are interpreted exactly as typed.
+  const batPath = buildCodexLoginBatPath();
+  const batContent = buildCodexLoginBatContent(input);
+  await writeFile(batPath, batContent, { encoding: "ascii" });
 
   await new Promise<void>((resolve, reject) => {
-    const child = spawn("cmd.exe", ["/c", "start", "cmd.exe", "/k", command], {
+    const child = spawn("cmd.exe", ["/c", "start", "", batPath], {
       cwd: input.workspaceRoot,
-      stdio: ["ignore", "ignore", "pipe"]
+      stdio: ["ignore", "ignore", "pipe"],
+      windowsHide: false
     });
 
     let stderr = "";
@@ -169,6 +186,28 @@ async function launchCodexLoginOnWindows(input: {
   });
 }
 
+export function buildCodexLoginBatPath(): string {
+  return join(tmpdir(), "screen-pilot-codex-login.bat");
+}
+
+export function buildCodexLoginBatContent(input: {
+  codexBin: string;
+  workspaceRoot: string;
+}): string {
+  // CRLF line endings are mandatory - LF-only .bat files misbehave on
+  // some cmd.exe versions and we enforce CRLF everywhere else in the
+  // repo via .gitattributes.
+  const lines = [
+    "@echo off",
+    `cd /d ${winQuote(input.workspaceRoot)}`,
+    `${winQuote(input.codexBin)} -c "model_reasoning_effort=high" login`,
+    "echo.",
+    "echo Codex login flow finished. You can close this window.",
+    "pause"
+  ];
+  return lines.join("\r\n") + "\r\n";
+}
+
 export function buildCodexLoginCommandWindows(input: {
   codexBin: string;
   workspaceRoot: string;

core/agent/test/codex-login.test.ts

@@ -2,7 +2,7 @@ import test from "node:test";
 import assert from "node:assert/strict";
 import { EventEmitter } from "node:events";
 import { PassThrough } from "node:stream";
-import { buildCodexLoginCommand, buildCodexLoginCommandWindows, parseCodexLoginStatus, readCodexLoginStatus } from "../src/codex-login.js";
+import { buildCodexLoginBatContent, buildCodexLoginCommand, buildCodexLoginCommandWindows, parseCodexLoginStatus, readCodexLoginStatus } from "../src/codex-login.js";
 import type { SpawnedProcessLike } from "../src/codex.js";
 
 class FakeProcess extends EventEmitter implements SpawnedProcessLike {
@@ -43,6 +43,32 @@ test("buildCodexLoginCommandWindows uses cd /d and double-quote escaping", () =>
   assert.match(command, /login$/);
 });
 
+test("buildCodexLoginBatContent writes an ASCII bat with CRLF line endings", () => {
+  const content = buildCodexLoginBatContent({
+    codexBin: "C:\\Program Files\\codex\\codex.exe",
+    workspaceRoot: "C:\\Users\\test\\my repo"
+  });
+
+  // CRLF everywhere, LF only as part of CRLF
+  assert.match(content, /\r\n/, "bat content must use CRLF");
+  for (let i = 0; i < content.length; i += 1) {
+    if (content.charCodeAt(i) === 0x0a && content.charCodeAt(i - 1) !== 0x0d) {
+      assert.fail("bat content must not contain bare LF line endings");
+    }
+  }
+
+  // Pure ASCII - zh-CN cmd.exe code page 936 cannot decode UTF-8 multi-byte sequences.
+  for (let i = 0; i < content.length; i += 1) {
+    const code = content.charCodeAt(i);
+    assert.ok(code <= 0x7f, `non-ASCII byte 0x${code.toString(16)} at offset ${i}`);
+  }
+
+  assert.match(content, /@echo off\r\n/);
+  assert.match(content, /cd \/d "C:\\Users\\test\\my repo"\r\n/);
+  assert.match(content, /"C:\\Program Files\\codex\\codex.exe" -c "model_reasoning_effort=high" login\r\n/);
+  assert.match(content, /\r\npause\r\n$/);
+});
+
 test("readCodexLoginStatus uses CLI status output", async () => {
   const child = new FakeProcess();