feat(endpoint): 端点默认 body_rules 机制与 Codex 规则回填

- EndpointDefinition 新增 default_body_rules 字段，openai:cli/compact 配置 Codex 默认规则
- 创建端点时若未指定 body_rules 则自动填充对应格式的默认值
- 新增 GET /defaults/{api_format}/body-rules 接口查询默认规则
- 前端 EndpointFormDialog 增加"重置请求体"按钮，支持一键恢复默认
- Alembic 迁移回填已有 Codex 端点的默认 body_rules
- 新增 metadata 和 endpoint 创建默认值的单元测试

tests/unit/test_admin_endpoint_create_defaults.py

@@ -0,0 +1,103 @@
+from types import SimpleNamespace
+
+import pytest
+
+from src.api.admin.endpoints import routes
+from src.api.admin.endpoints.routes import AdminCreateProviderEndpointAdapter
+from src.models.database import Provider, ProviderEndpoint
+from src.models.endpoint_models import ProviderEndpointCreate
+
+
+class _FakeQuery:
+    def __init__(self, result: object | None) -> None:
+        self._result = result
+
+    def filter(self, *_args: object, **_kwargs: object) -> "_FakeQuery":
+        return self
+
+    def first(self) -> object | None:
+        return self._result
+
+
+class _FakeDB:
+    def __init__(self, provider: object) -> None:
+        self.provider = provider
+        self.added: ProviderEndpoint | None = None
+
+    def query(self, model: object) -> _FakeQuery:
+        if model is Provider:
+            return _FakeQuery(self.provider)
+        if model is ProviderEndpoint:
+            return _FakeQuery(None)
+        raise AssertionError(f"unexpected model: {model}")
+
+    def add(self, obj: ProviderEndpoint) -> None:
+        self.added = obj
+
+    def commit(self) -> None:
+        return None
+
+    def refresh(self, _obj: ProviderEndpoint) -> None:
+        return None
+
+
+async def _noop_invalidate_cache() -> None:
+    return None
+
+
+@pytest.mark.asyncio
+async def test_create_endpoint_injects_default_body_rules_when_missing(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.setattr(routes, "invalidate_models_list_cache", _noop_invalidate_cache)
+    monkeypatch.setattr(
+        routes,
+        "get_default_body_rules_for_endpoint",
+        lambda _fmt: [{"action": "drop", "path": "max_output_tokens"}],
+    )
+
+    db = _FakeDB(
+        provider=SimpleNamespace(id="p1", name="P1", provider_type="custom"),
+    )
+    adapter = AdminCreateProviderEndpointAdapter(
+        provider_id="p1",
+        endpoint_data=ProviderEndpointCreate(
+            provider_id="p1",
+            api_format="openai:cli",
+            base_url="https://api.example.com",
+        ),
+    )
+
+    await adapter.handle(SimpleNamespace(db=db))  # type: ignore[arg-type]
+    assert db.added is not None
+    assert db.added.body_rules == [{"action": "drop", "path": "max_output_tokens"}]
+
+
+@pytest.mark.asyncio
+async def test_create_endpoint_keeps_user_body_rules_when_provided(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.setattr(routes, "invalidate_models_list_cache", _noop_invalidate_cache)
+    monkeypatch.setattr(
+        routes,
+        "get_default_body_rules_for_endpoint",
+        lambda _fmt: [{"action": "drop", "path": "max_output_tokens"}],
+    )
+
+    user_rules = [{"action": "set", "path": "metadata.source", "value": "user"}]
+    db = _FakeDB(
+        provider=SimpleNamespace(id="p1", name="P1", provider_type="custom"),
+    )
+    adapter = AdminCreateProviderEndpointAdapter(
+        provider_id="p1",
+        endpoint_data=ProviderEndpointCreate(
+            provider_id="p1",
+            api_format="openai:cli",
+            base_url="https://api.example.com",
+            body_rules=user_rules,
+        ),
+    )
+
+    await adapter.handle(SimpleNamespace(db=db))  # type: ignore[arg-type]
+    assert db.added is not None
+    assert db.added.body_rules == user_rules