feat(templates): F3b 模板库 repo + 端点（GET/POST/DELETE /templates）

- TemplateRepo/SqlTemplateRepo（list/create/delete，owner stub 过滤，只 flush 端点 commit）
- schemas/templates.py（title/body min_length=1→422）+ routers/templates.py（删不存在→404）+ main 注册
- 单测：repo CRUD/owner 隔离/frozen + 端点 201/列出/204/422×2/404

apps/api/tests/test_templates.py

@@ -0,0 +1,127 @@
+"""F3b GET/POST/DELETE /templates 端点（内存替身，无 DB/无网络）。
+
+覆盖：
+- POST 201 + 回显 + 端点 commit；GET 列出；DELETE 204 + commit；
+- 空 title → 422、空 body → 422（schema `min_length=1`，FastAPI 422）；
+- 删不存在 → 404（repo.delete 返 False → AppError NOT_FOUND）。
+"""
+
+from __future__ import annotations
+
+import os
+import uuid
+
+import httpx
+import pytest
+from cryptography.fernet import Fernet
+from fakes_projects import FakeSession
+from ww_core.domain.template_repo import TemplateCreate, TemplateView
+
+
+class _FakeTemplateRepo:
+    def __init__(self) -> None:
+        self.rows: dict[uuid.UUID, TemplateView] = {}
+
+    async def create(self, owner_id: uuid.UUID, data: TemplateCreate) -> TemplateView:
+        view = TemplateView(
+            id=uuid.uuid4(),
+            title=data.title,
+            body=data.body,
+            category=data.category,
+            tool_key=data.tool_key,
+        )
+        self.rows[view.id] = view
+        return view
+
+    async def list_for_owner(self, owner_id: uuid.UUID) -> list[TemplateView]:
+        return list(self.rows.values())
+
+    async def delete(self, owner_id: uuid.UUID, template_id: uuid.UUID) -> bool:
+        if template_id in self.rows:
+            del self.rows[template_id]
+            return True
+        return False
+
+
+def _make_client() -> tuple[httpx.AsyncClient, _FakeTemplateRepo, FakeSession]:
+    os.environ.setdefault("CREDENTIAL_ENC_KEY", Fernet.generate_key().decode())
+    from ww_api.main import create_app
+    from ww_api.services.project_deps import get_template_repo
+    from ww_db import get_session
+
+    repo = _FakeTemplateRepo()
+    session = FakeSession()
+
+    app = create_app()
+    app.dependency_overrides[get_template_repo] = lambda: repo
+    app.dependency_overrides[get_session] = lambda: session
+    transport = httpx.ASGITransport(app=app)
+    client = httpx.AsyncClient(transport=transport, base_url="http://test")
+    return client, repo, session
+
+
+@pytest.mark.asyncio
+async def test_create_template_returns_201_and_commits() -> None:
+    client, repo, session = _make_client()
+    async with client:
+        resp = await client.post(
+            "/templates",
+            json={"title": "爽文开局", "body": "主角穿越...", "tool_key": "expand"},
+        )
+    assert resp.status_code == 201
+    body = resp.json()
+    assert body["title"] == "爽文开局"
+    assert body["body"] == "主角穿越..."
+    assert body["tool_key"] == "expand"
+    assert session.commits == 1
+    assert len(repo.rows) == 1
+
+
+@pytest.mark.asyncio
+async def test_list_templates_returns_created() -> None:
+    client, repo, _session = _make_client()
+    async with client:
+        await client.post("/templates", json={"title": "a", "body": "b"})
+        resp = await client.get("/templates")
+    assert resp.status_code == 200
+    items = resp.json()
+    assert len(items) == 1
+    assert items[0]["title"] == "a"
+
+
+@pytest.mark.asyncio
+async def test_create_template_empty_title_returns_422() -> None:
+    client, _repo, _session = _make_client()
+    async with client:
+        resp = await client.post("/templates", json={"title": "", "body": "b"})
+    assert resp.status_code == 422
+
+
+@pytest.mark.asyncio
+async def test_create_template_empty_body_returns_422() -> None:
+    client, _repo, _session = _make_client()
+    async with client:
+        resp = await client.post("/templates", json={"title": "a", "body": ""})
+    assert resp.status_code == 422
+
+
+@pytest.mark.asyncio
+async def test_delete_template_returns_204_and_commits() -> None:
+    client, repo, session = _make_client()
+    async with client:
+        created = await client.post("/templates", json={"title": "a", "body": "b"})
+        tid = created.json()["id"]
+        resp = await client.delete(f"/templates/{tid}")
+    assert resp.status_code == 204
+    assert session.commits == 2
+    assert repo.rows == {}
+
+
+@pytest.mark.asyncio
+async def test_delete_missing_template_returns_404() -> None:
+    client, _repo, session = _make_client()
+    async with client:
+        resp = await client.delete(f"/templates/{uuid.uuid4()}")
+    assert resp.status_code == 404
+    assert resp.json()["error"]["code"] == "NOT_FOUND"
+    assert session.commits == 0