feat: M1 — 立项→写章草稿(SSE)→自动保存；连一家 provider

- 薄自建 LLM 网关：OpenAI 兼容适配器(DeepSeek) + instructor 结构化输出 + usage_ledger 记账 + 档位路由
- 记忆服务 assemble：确定性选择(显式+主角+近况) + 渲染卡 + 缓存断点(中性文本)
- LangGraph 写章节点 + Postgres checkpointer + SSE 归一(token/done/error)
- API：立项 + 写章 draft(SSE) + PUT 自动保存 + 提供商凭据(Fernet 加密/测试连接)
- 前端：AppShell + 作品库 + 5 步立项向导 + 写作工作台(流式打字机+自动保存) + 设置页
- M1 E2E：真实 DB + mock 网关零 token 走通闭环

apps/api/tests/test_projects.py

@@ -0,0 +1,210 @@
+"""T1.4 端点测试：立项 CRUD + 写章 SSE + 自动保存（内存替身，无 DB/无网络）。
+
+DoD：端点入 OpenAPI；POST draft 回 SSE 流（mock 网关验证）；PUT draft 幂等。
+"""
+
+from __future__ import annotations
+
+import uuid
+
+import httpx
+import pytest
+from fakes_projects import FakeChapterRepo, FakeProjectRepo, FakeWriterGateway
+from ww_core.domain.repositories import (
+    CharacterView,
+    DigestView,
+    ForeshadowView,
+    MemoryRepos,
+    OutlineView,
+    RuleView,
+    StyleView,
+    WorldEntityView,
+)
+from ww_shared import ErrorCode
+
+
+class _EmptyOutlineRepo:
+    async def get(self, project_id: uuid.UUID, chapter_no: int) -> OutlineView | None:
+        return None
+
+
+class _EmptyCharacterRepo:
+    async def list_for_project(self, project_id: uuid.UUID) -> list[CharacterView]:
+        return []
+
+
+class _EmptyWorldEntityRepo:
+    async def list_for_project(self, project_id: uuid.UUID) -> list[WorldEntityView]:
+        return []
+
+
+class _EmptyDigestRepo:
+    async def recent(self, project_id: uuid.UUID, k: int) -> list[DigestView]:
+        return []
+
+
+class _EmptyForeshadowRepo:
+    async def list_for_codes(self, project_id: uuid.UUID, codes: list[str]) -> list[ForeshadowView]:
+        return []
+
+
+class _EmptyStyleRepo:
+    async def latest(self, project_id: uuid.UUID) -> StyleView | None:
+        return None
+
+
+class _EmptyRulesRepo:
+    async def all_for_project(self, project_id: uuid.UUID) -> list[RuleView]:
+        return []
+
+
+def _empty_memory_repos() -> MemoryRepos:
+    return MemoryRepos(
+        outline=_EmptyOutlineRepo(),
+        character=_EmptyCharacterRepo(),
+        world_entity=_EmptyWorldEntityRepo(),
+        digest=_EmptyDigestRepo(),
+        foreshadow=_EmptyForeshadowRepo(),
+        style=_EmptyStyleRepo(),
+        rules=_EmptyRulesRepo(),
+    )
+
+
+def _make_client(
+    *,
+    project_repo: FakeProjectRepo | None = None,
+    chapter_repo: FakeChapterRepo | None = None,
+    gateway: FakeWriterGateway | None = None,
+) -> tuple[httpx.AsyncClient, FakeProjectRepo, FakeChapterRepo, FakeWriterGateway]:
+    import os
+
+    os.environ.setdefault("CREDENTIAL_ENC_KEY", "x" * 44)
+    from ww_api.main import create_app
+    from ww_api.services.project_deps import (
+        get_chapter_repo,
+        get_memory_repos,
+        get_project_repo,
+        get_writer_gateway,
+    )
+
+    project_repo = project_repo or FakeProjectRepo()
+    chapter_repo = chapter_repo or FakeChapterRepo()
+    gateway = gateway or FakeWriterGateway()
+
+    app = create_app()
+    app.dependency_overrides[get_project_repo] = lambda: project_repo
+    app.dependency_overrides[get_chapter_repo] = lambda: chapter_repo
+    app.dependency_overrides[get_memory_repos] = _empty_memory_repos
+    app.dependency_overrides[get_writer_gateway] = lambda: gateway
+    transport = httpx.ASGITransport(app=app)
+    client = httpx.AsyncClient(transport=transport, base_url="http://test")
+    return client, project_repo, chapter_repo, gateway
+
+
+@pytest.mark.asyncio
+async def test_create_project_returns_201() -> None:
+    client, _, _, _ = _make_client()
+    async with client:
+        resp = await client.post(
+            "/projects",
+            json={"title": "我的网文", "genre": "玄幻", "selling_points": ["爽点密集"]},
+        )
+    assert resp.status_code == 201
+    body = resp.json()
+    assert body["title"] == "我的网文"
+    assert body["genre"] == "玄幻"
+    assert body["selling_points"] == ["爽点密集"]
+    assert uuid.UUID(body["id"])
+
+
+@pytest.mark.asyncio
+async def test_list_projects() -> None:
+    client, repo, _, _ = _make_client()
+    async with client:
+        await client.post("/projects", json={"title": "甲"})
+        await client.post("/projects", json={"title": "乙"})
+        resp = await client.get("/projects")
+    assert resp.status_code == 200
+    titles = {p["title"] for p in resp.json()["projects"]}
+    assert titles == {"甲", "乙"}
+
+
+@pytest.mark.asyncio
+async def test_get_project_detail() -> None:
+    client, _, _, _ = _make_client()
+    async with client:
+        created = (await client.post("/projects", json={"title": "详情"})).json()
+        resp = await client.get(f"/projects/{created['id']}")
+    assert resp.status_code == 200
+    assert resp.json()["title"] == "详情"
+
+
+@pytest.mark.asyncio
+async def test_get_unknown_project_404() -> None:
+    client, _, _, _ = _make_client()
+    async with client:
+        resp = await client.get(f"/projects/{uuid.uuid4()}")
+    assert resp.status_code == 404
+    assert resp.json()["error"]["code"] == ErrorCode.NOT_FOUND
+
+
+@pytest.mark.asyncio
+async def test_create_project_rejects_blank_title() -> None:
+    client, _, _, _ = _make_client()
+    async with client:
+        resp = await client.post("/projects", json={"title": ""})
+    assert resp.status_code == 422
+
+
+@pytest.mark.asyncio
+async def test_draft_stream_yields_sse_tokens_and_done() -> None:
+    gateway = FakeWriterGateway(chunks=["阿福", "走进门。"])
+    client, _, _, _ = _make_client(gateway=gateway)
+    pid = uuid.uuid4()
+    async with client:
+        resp = await client.post(f"/projects/{pid}/chapters/1/draft")
+    assert resp.status_code == 200
+    assert resp.headers["content-type"].startswith("text/event-stream")
+    text = resp.text
+    assert "event: token" in text
+    assert '"text": "阿福"' in text
+    assert "event: done" in text
+    # done 带累计长度（不回灌全文）
+    assert '"length": 6' in text
+    # 网关确实被调用，且只传 tier（不传具体 model）
+    assert len(gateway.requests) == 1
+    assert gateway.requests[0].tier == "writer"
+
+
+@pytest.mark.asyncio
+async def test_draft_stream_maps_error_to_sse_error_event() -> None:
+    from ww_shared import AppError
+
+    gateway = FakeWriterGateway(chunks=["半段"], error=AppError(ErrorCode.LLM_UNAVAILABLE, "boom"))
+    client, _, _, _ = _make_client(gateway=gateway)
+    pid = uuid.uuid4()
+    async with client:
+        resp = await client.post(f"/projects/{pid}/chapters/1/draft")
+    assert resp.status_code == 200
+    text = resp.text
+    assert "event: token" in text
+    assert "event: error" in text
+    assert ErrorCode.LLM_UNAVAILABLE in text
+
+
+@pytest.mark.asyncio
+async def test_put_draft_is_idempotent() -> None:
+    chapter_repo = FakeChapterRepo()
+    client, _, _, _ = _make_client(chapter_repo=chapter_repo)
+    pid = uuid.uuid4()
+    async with client:
+        r1 = await client.put(f"/projects/{pid}/chapters/3/draft", json={"text": "初稿"})
+        r2 = await client.put(f"/projects/{pid}/chapters/3/draft", json={"text": "改稿更长"})
+    assert r1.status_code == 200
+    assert r2.status_code == 200
+    # 同章节只一条草稿（版次不爆炸）
+    assert len(chapter_repo.drafts) == 1
+    saved = chapter_repo.drafts[(pid, 3)]
+    assert saved.content == "改稿更长"
+    assert saved.version == 1
+    assert r2.json()["length"] == len("改稿更长")