pr 超时：git/gh 子进程默认 120 秒超时，超时转 502 不挂 handler

此前 /pr 的子进程调用没有超时：远端通路卡死时 handler
线程永久挂住，客户端断开也收不回来。_run 真实路径一律
带 timeout（默认 120 秒，CLOUD_PR_SUBPROCESS_TIMEOUT
可改，非法值回落默认），超时杀子进程、返回 124，调用方
按原有失败路径处理（push/pr_create/commit 抛 PrStepError，
探针按跳过处理）。App 路径的 GitHub API 调用已有 30 秒
超时，本次不动。测试：真实 sleep 超时 2 个、环境变量
2 项、超时映射 push/commit 2 个

cloud/tests/test_pr_timeout.py

@@ -0,0 +1,133 @@
+"""pr.py 子进程超时单测。
+
+真实路径：sleep 命令实测超时真的杀进程、真的按时返回
+（不是等命令跑完）；环境变量改超时、非法值回落默认。
+映射路径：假 runner 回 124 超时结果时，push/commit 按原有
+失败路径抛 PrStepError（step 对得上），不挂住、不误报成功。
+"""
+
+import os
+import sys
+import tempfile
+import time
+import unittest
+from pathlib import Path
+from types import SimpleNamespace
+
+try:
+    from cloud.pr import (
+        PrStepError,
+        _pr_subprocess_timeout,
+        _run,
+        create_task_pr,
+    )
+except ImportError:
+    sys.path.insert(0, str(Path(__file__).resolve().parents[2]))
+    from cloud.pr import (
+        PrStepError,
+        _pr_subprocess_timeout,
+        _run,
+        create_task_pr,
+    )
+
+
+def _result(returncode=0, stdout="", stderr=""):
+    return SimpleNamespace(returncode=returncode, stdout=stdout,
+                           stderr=stderr)
+
+
+class _Git:
+    """假 git：push/commit 的失败模式可配，其余按脚本回。"""
+
+    def __init__(self, push="ok", commit="nothing"):
+        self.push = push
+        self.commit = commit
+
+    def __call__(self, cmd, cwd):
+        if "remote" in cmd:
+            return _result(0, "https://github.com/octo/a.git\n")
+        if "branch" in cmd:
+            return _result(0, "host/t1\n")
+        if "add" in cmd:
+            return _result(0, "")
+        if "commit" in cmd:
+            if self.commit == "timeout":
+                return _result(124, "", "command timed out")
+            return _result(1, "",
+                           "nothing to commit, working tree clean")
+        if "push" in cmd:
+            if self.push == "timeout":
+                return _result(124, "", "command timed out")
+            return _result(0, "")
+        return _result(0, "")
+
+
+def _gh(cmd, cwd):
+    if cmd[:2] == ["gh", "auth"]:
+        return _result(0, "", "")
+    if cmd[:2] == ["gh", "pr"]:
+        return _result(0, "https://github.com/octo/a/pull/9\n")
+    return _result(0, "")
+
+
+class RunTimeoutTestCase(unittest.TestCase):
+    def test_real_sleep_is_killed_on_timeout(self):
+        start = time.monotonic()
+        r = _run(["sleep", "3"], timeout=1)
+        elapsed = time.monotonic() - start
+        self.assertEqual(r.returncode, 124)
+        self.assertIn("timed out", r.stderr)
+        self.assertLess(elapsed, 2.5)
+
+    def test_fast_command_ok_with_default_timeout(self):
+        r = _run(["true"])
+        self.assertEqual(r.returncode, 0)
+
+    def test_env_override_and_invalid_fallback(self):
+        old = os.environ.get("CLOUD_PR_SUBPROCESS_TIMEOUT")
+        try:
+            os.environ["CLOUD_PR_SUBPROCESS_TIMEOUT"] = "1"
+            self.assertEqual(_pr_subprocess_timeout(), 1)
+            start = time.monotonic()
+            r = _run(["sleep", "3"])
+            self.assertEqual(r.returncode, 124)
+            self.assertLess(time.monotonic() - start, 2.5)
+            os.environ["CLOUD_PR_SUBPROCESS_TIMEOUT"] = "abc"
+            self.assertEqual(_pr_subprocess_timeout(), 120)
+            os.environ["CLOUD_PR_SUBPROCESS_TIMEOUT"] = "0"
+            self.assertEqual(_pr_subprocess_timeout(), 120)
+        finally:
+            if old is None:
+                os.environ.pop("CLOUD_PR_SUBPROCESS_TIMEOUT", None)
+            else:
+                os.environ["CLOUD_PR_SUBPROCESS_TIMEOUT"] = old
+
+
+class TimeoutMappingTestCase(unittest.TestCase):
+    def _worktree(self, tmp):
+        d = os.path.join(tmp, "t1")
+        os.makedirs(d, exist_ok=True)
+        return d
+
+    def test_push_timeout_is_pr_step_error(self):
+        with tempfile.TemporaryDirectory() as tmp:
+            self._worktree(tmp)
+            with self.assertRaises(PrStepError) as ctx:
+                create_task_pr("t1", 1, worktrees_root=tmp,
+                               git_runner=_Git(push="timeout"),
+                               gh_runner=_gh, gh_which="/usr/bin/gh")
+            self.assertEqual(ctx.exception.step, "push")
+            self.assertIn("timed out", ctx.exception.message)
+
+    def test_commit_timeout_is_pr_step_error(self):
+        with tempfile.TemporaryDirectory() as tmp:
+            self._worktree(tmp)
+            with self.assertRaises(PrStepError) as ctx:
+                create_task_pr("t1", 1, worktrees_root=tmp,
+                               git_runner=_Git(commit="timeout"),
+                               gh_runner=_gh, gh_which="/usr/bin/gh")
+            self.assertEqual(ctx.exception.step, "commit")
+
+
+if __name__ == "__main__":
+    unittest.main()