align: 第二批：把技能包播种进租户 codex-home

仿 websearch MCP 播种，默认关：
- cloud/skill_seed.py：cloud/skills/ 的 SKILL.md 拷进租户
  codex-home/.agents/skills/（个人级技能路径，见模块
  文档的路径依据与诚实边界）；幂等，租户改过的文件
  绝不覆盖（上报 differs），缺包不阻塞任务。
- cloud/worker.py：新增 --seed-skills，_tenant_dirs 里
  调用播种；老租户下一次任务自动合并；播种失败只记
  日志、不阻塞任务（技能是可选流程说明）。
- cloud/tests/test_skill_seed_worker.py：播种助手 + worker
  开关，仿 test_websearch_worker.py 的结构。
- docs/chatgpt-codex-alignment.md：补第二批说明与实测
  待办（真实 Docker 任务 skills/list + $live-info 调用，
  通过前不宣称生产任务已能用这些技能）。

验证：skill_seed + chatgpt skills + websearch worker
共 14 项全过。本批不改生产配置、不部署，autoscaler
加 --seed-skills 是部署时另行的主机步骤。

cloud/tests/test_skill_seed_worker.py

@@ -0,0 +1,132 @@
+"""Worker wiring for ChatGPT-Codex-alignment skills: tenant seeding.
+
+Mirrors test_websearch_worker.py: no Docker, no network, no real
+model. _tenant_dirs runs against temp dirs; the skill pack used
+here is the real cloud/skills/ pack, so a broken pack fails here
+before it ever reaches a tenant.
+"""
+
+import os
+import sys
+import tempfile
+import unittest
+from pathlib import Path
+
+try:
+    from cloud.server import init_db
+    from cloud.worker import Worker
+    from cloud.skill_seed import ensure_codex_home_skills, list_skills
+except ImportError:
+    sys.path.insert(0, str(Path(__file__).resolve().parents[2]))
+    from cloud.server import init_db
+    from cloud.worker import Worker
+    from cloud.skill_seed import ensure_codex_home_skills, list_skills
+
+
+class SkillSeedHelperTestCase(unittest.TestCase):
+    def setUp(self):
+        self.tmp = tempfile.TemporaryDirectory()
+
+    def tearDown(self):
+        self.tmp.cleanup()
+
+    def _src(self):
+        src = os.path.join(self.tmp.name, "pack")
+        for name in ("live-info", "document-tools"):
+            d = os.path.join(src, name)
+            os.makedirs(d, exist_ok=True)
+            open(os.path.join(d, "SKILL.md"), "w").write(
+                "---\nname: %s\ndescription: test\n---\nbody\n" % name)
+        return src
+
+    def test_copy_idempotent_and_missing_source(self):
+        home = os.path.join(self.tmp.name, "home")
+        out = ensure_codex_home_skills(home, self._src())
+        self.assertEqual(sorted(out["skills_copied"]),
+                         ["document-tools", "live-info"])
+        self.assertEqual(out["skills_skipped_differ"], [])
+        out2 = ensure_codex_home_skills(home, self._src())
+        self.assertEqual(out2["skills_copied"], [])
+        out3 = ensure_codex_home_skills(
+            os.path.join(self.tmp.name, "home2"),
+            os.path.join(self.tmp.name, "no-such-pack"))
+        self.assertEqual(out3["skills_copied"], [])
+
+    def test_tenant_modified_skill_is_never_overwritten(self):
+        home = os.path.join(self.tmp.name, "home")
+        src = self._src()
+        ensure_codex_home_skills(home, src)
+        dest = os.path.join(home, ".agents", "skills",
+                            "live-info", "SKILL.md")
+        open(dest, "w").write("tenant edited version\n")
+        out = ensure_codex_home_skills(home, src)
+        self.assertEqual(out["skills_skipped_differ"], ["live-info"])
+        self.assertEqual(open(dest).read(), "tenant edited version\n")
+
+    def test_real_pack_lists_three_skills(self):
+        names = [n for n, _p in list_skills()]
+        self.assertEqual(names,
+                         ["document-tools", "image-workflow",
+                          "live-info"])
+
+
+class WorkerSkillSeedTestCase(unittest.TestCase):
+    def setUp(self):
+        self.tmp = tempfile.TemporaryDirectory()
+        self.db_path = os.path.join(self.tmp.name, "control.db")
+        init_db(self.db_path)
+        self.template_home = os.path.join(self.tmp.name, "tpl-home")
+        os.makedirs(self.template_home)
+        open(os.path.join(self.template_home, "config.toml"),
+             "w").write('[model_provider.xcmapi]\n'
+                         'base_url="https://xcmapi.org/v1"\n')
+        self.template_repo = os.path.join(self.tmp.name, "tpl-repo")
+        os.makedirs(os.path.join(self.template_repo, ".git"))
+        open(os.path.join(self.template_repo, "sample.py"),
+             "w").write("def add(a, b):\n    return a + b\n")
+
+    def tearDown(self):
+        self.tmp.cleanup()
+
+    def _worker(self, **kwargs):
+        kwargs.setdefault("env", {"XCM_API_KEY": "test-placeholder"})
+        kwargs.setdefault("tenants_root",
+                          os.path.join(self.tmp.name, "tenants"))
+        kwargs.setdefault("tenant_template_home", self.template_home)
+        kwargs.setdefault("tenant_template_repo", self.template_repo)
+        kwargs.setdefault("tenant_isolation", True)
+        return Worker(self.db_path, "/fake/host.py", **kwargs)
+
+    def _skill_path(self, dirs, name):
+        return os.path.join(dirs["codex_home"], ".agents", "skills",
+                            name, "SKILL.md")
+
+    def test_flag_off_is_old_behaviour(self):
+        worker = self._worker()
+        self.assertFalse(worker.seed_skills)
+        dirs = worker._tenant_dirs("projA")
+        self.assertFalse(os.path.exists(
+            os.path.join(dirs["codex_home"], ".agents", "skills")))
+
+    def test_flag_on_seeds_real_pack(self):
+        worker = self._worker(seed_skills=True)
+        dirs = worker._tenant_dirs("projA")
+        for name in ("live-info", "document-tools", "image-workflow"):
+            path = self._skill_path(dirs, name)
+            self.assertTrue(os.path.exists(path), path)
+            self.assertIn("name: %s" % name, open(path).read())
+
+    def test_old_tenant_merges_and_user_edit_survives(self):
+        worker = self._worker()
+        dirs = worker._tenant_dirs("projA")
+        worker2 = self._worker(seed_skills=True)
+        worker2._tenant_dirs("projA")
+        path = self._skill_path(dirs, "live-info")
+        self.assertTrue(os.path.exists(path))
+        open(path, "w").write("tenant edited version\n")
+        worker2._tenant_dirs("projA")
+        self.assertEqual(open(path).read(), "tenant edited version\n")
+
+
+if __name__ == "__main__":
+    unittest.main()