feat: 装配切换——main/服务构造线/conftest 迁至 Registry（含默认租户过渡兜底）

- main.py: 删全局 engine/async_session;lifespan 装配 TenantRegistry
  (seed_profiles → 仓库根 tenants/,路径锚定),预热默认租户 jiancai 挂
  app.state.default_runtime,逐 active 租户(库文件已存在)跑
  sweep_stale_pending,退出 dispose_all。app.state.registry 预置即沿用
  (测试注入缝)
- routes/runtime.py(过渡,Task 7 删): get_runtime——state.tenant 优先,
  缺省落 default_runtime;chat.py/chat_rest.py 全部改走它,消除
  main↔routes 循环依赖
- ConversationManager 构造线: 新增 runtime 可选参(持 session_factory/
  compiled_wall/config 引用;prompts 仍模块级,Task 6;业务接线 Task 9),
  fire_pending_pushes 随任务传 session_factory(后台写回派发租户的库)
- lead_push_service: 去 app.main import;写库入口显式收 session_factory,
  模块级 async_session=None 仅作测试注入兜底
- conftest: client 夹具 = 每测试独立 Registry(tmp data_dir)+ 真实
  lifespan 在 TestClient 循环内预热;删 _dispose_main_engine;
  async_db 保持 NullPool(跨 asyncio.run 循环安全,刻意不换 Registry 引擎)
- 测试仅动夹具/桩签名(断言零改动): wiring 桩补 session_factory 形参;
  history-404 用例改经真实 WS 路由造 widget 会话(引擎常驻连接绑定
  TestClient 循环,测试线程不得直开 session_factory)

Co-Authored-By: Claude Code <noreply@anthropic.com>

tests/conftest.py

@@ -1,27 +1,23 @@
-import os
-import tempfile
 import asyncio
+import os
+import shutil
+import tempfile
+from pathlib import Path
 
 import pytest
-from sqlalchemy.ext.asyncio import create_async_engine, async_sessionmaker
+from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
 from sqlalchemy.pool import NullPool
 
 from app.engine.models import Base
 
-# `chat_rest` is created in Task A4. Tolerate its absence so earlier tasks
-# (e.g. A0's /health smoke) can use the `client` fixture without it.
-# Import `app.main` FIRST so the natural main -> chat_rest load order resolves
-# (chat_rest does `from app.main import async_session`; if conftest imports
-# chat_rest before main is loaded, main's `from chat_rest import router` hits
-# a partially-initialized module -> circular ImportError).
-_HAS_CHAT_REST = False
-chat_rest_mod = None
-try:
-    import app.main  # noqa: F401
-    import app.engine.routes.chat_rest as chat_rest_mod
-    _HAS_CHAT_REST = True
-except ModuleNotFoundError:
-    pass
+# Task 5b 装配切换: app 不再有全局 engine/async_session——旧 conftest 里
+# "先 import app.main 再 import chat_rest"的循环导入次序坑随全局单例一并
+# 消失(routes 不再反向 import app.main),直接导入即可。
+from app.main import app
+from app.platform.registry import TenantRegistry
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+SEED_DIR = REPO_ROOT / "seed_profiles"
 
 
 async def _create_all(engine):
@@ -29,34 +25,15 @@ async def _create_all(engine):
         await conn.run_sync(Base.metadata.create_all)
 
 
-@pytest.fixture(scope="session", autouse=True)
-def _dispose_main_engine():
-    """Dispose `app.main.engine` at session end.
-
-    Best-effort cleanup: explicitly disposing the app-level engine before
-    interpreter shutdown reduces (but does NOT eliminate) the noisy
-    `Windows fatal exception: access violation` traces that aiosqlite worker
-    threads emit when interrupted mid-cleanup at interpreter exit.
-
-    Reality check on Windows:
-    - All tests pass and pytest exits 0; the traces are written to stderr
-      AFTER the run completes and do not affect pass/fail or the exit code.
-    - They originate from aiosqlite background threads being torn down by the
-      interpreter and are harmless.
-    - They do not occur on Linux/CI.
-    """
-    yield
-    from app.main import engine as main_engine
-    try:
-        asyncio.run(main_engine.dispose())
-    except Exception:
-        pass
-
-
 @pytest.fixture
 def async_db():
     """Fresh temp-file SQLite sessionmaker for direct async-DB tests
     (e.g. testing ConversationManager without HTTP). Isolated per test.
+
+    刻意不走 Registry 引擎: 本夹具被各测试反复 asyncio.run(每次全新事件
+    循环),NullPool 连接即借即还才能跨循环安全;Registry 的 pool=2 常驻
+    连接与创建它的循环绑定,只能活在单一事件循环里(client 夹具的
+    TestClient 循环,见下)。
     """
     fd, path = tempfile.mkstemp(suffix=".db")
     os.close(fd)
@@ -84,37 +61,25 @@ def _reset_rate_limit():
 
 
 @pytest.fixture
-def client(monkeypatch):
-    """Temporary file-SQLite TestClient with `chat_rest.async_session` overridden.
+def client(tmp_path):
+    """TestClient + 每测试独立 Registry(tmp_path 作 data_dir)。
 
-    Design notes:
-    - File DB (not :memory:) avoids the StaticPool cross-loop reuse pitfall.
-    - `NullPool` closes each connection when the session returns it, so no
-      aiosqlite worker thread outlives the event loop that created it.
-      Together with `_dispose_main_engine`, this REDUCES but does NOT
-      eliminate the harmless Windows access-violation stderr traces described
-      above; it has no effect on test correctness or on Linux/CI.
-    - Monkeypatching the module-level `async_session` binding in `chat_rest`
-      works because the route handlers resolve it as a module global at call.
+    - 预置 app.state.registry(测试注入缝): lifespan 见 registry 已挂则
+      沿用,不再加载仓库 seed_profiles/tenants——每测试拿到全新租户库,
+      与生产数据互不污染。
+    - 默认租户(jiancai)的 engine 由 lifespan 在 TestClient 的 portal 事件
+      循环内预热,后续请求也在同一循环处理(连接/循环绑定安全)。测试
+      线程需要直接造数时不得用该 engine——asyncio.run 另起循环,跨循环
+      复用常驻连接会死锁;直连断言走 async_db,或经真实路由(WS/REST)。
+    - 退出: lifespan finally 里 registry.dispose_all()(Windows 文件锁,
+      不关则 tmp 目录删不掉),随后清理 tmp 目录。
     """
     from fastapi.testclient import TestClient
-    from app.main import app
 
-    fd, path = tempfile.mkstemp(suffix=".db")
-    os.close(fd)
-    engine = create_async_engine(
-        f"sqlite+aiosqlite:///{path}", poolclass=NullPool
-    )
-    asyncio.run(_create_all(engine))
-    sm = async_sessionmaker(engine, expire_on_commit=False)
-    if _HAS_CHAT_REST:
-        monkeypatch.setattr(chat_rest_mod, "async_session", sm)
-
-    with TestClient(app) as c:
-        yield c
-
-    asyncio.run(engine.dispose())
+    registry = TenantRegistry.load_from_dir(SEED_DIR, data_dir=tmp_path)
+    app.state.registry = registry
     try:
-        os.remove(path)
-    except PermissionError:
-        pass
+        with TestClient(app) as c:
+            yield c
+    finally:
+        shutil.rmtree(tmp_path, ignore_errors=True)