feat: M3 — 伏笔账本 + 节奏引擎 + 大纲（含并发记账 bugfix）

- 伏笔账本：纯函数状态机(OPEN/PARTIAL/CLOSED/OVERDUE) + ForeshadowLedger repo；验收后到期扫描(BackgroundTask 自建 session 置 OVERDUE)；登记/状态变更端点
- 节奏 + 三审齐：foreshadow-analyst + pace-checker 并入 LangGraph 并行审(REVIEW_SPECS)，collect 分列落 chapter_reviews(conflicts/foreshadow_sug/pace)，review SSE 加 foreshadow/pace 事件
- 大纲：outliner Agent 产 OutlineResult(含 foreshadow_windows)，POST /outline 逐章 upsert outline 表；GET /foreshadow?status= 看板
- 前端：伏笔四泳道看板(OVERDUE 琥珀) + 大纲编辑器(窗口徽标) + 节奏节拍图(▁▃▅) + 审稿页消费 foreshadow/pace SSE
- bugfix(T3.8)：并行三审共用请求 session 记账触发 'Session is already flushing' → foreshadow/pace 静默丢失；SqlAlchemyLedgerSink.record 改 add-only(靠端点/事务 commit)，加并发回归测试
- M3 E2E：真实 DB + mock 网关零 token 走通 埋设→进展→验收后扫描 OVERDUE→看板 + 大纲含窗口 + 三审齐 SSE/留痕；E2E 暴露并钉住上述 bug
- 门禁绿：mypy 111 / pytest 228(0 xfailed) / alembic 无漂移；前端 gen:api/lint/tsc/vitest 69/build

apps/api/tests/test_outline_context.py

@@ -0,0 +1,63 @@
+"""T3.5 大纲注入上下文组装单测（确定性纯函数；ARCH §5.4）。
+
+断言：四源（设定/伏笔/人物/世界观）都进文本、排序确定（同输入同输出）、空源不炸。
+"""
+
+from __future__ import annotations
+
+from ww_api.services.outline_context import build_outline_context
+from ww_core.domain import ForeshadowLedgerView
+from ww_core.domain.project_repo import ProjectView
+from ww_core.domain.repositories import CharacterView, WorldEntityView
+
+
+def _project() -> ProjectView:
+    import uuid
+
+    return ProjectView(
+        id=uuid.UUID(int=1),
+        title="逆天剑帝",
+        genre="玄幻",
+        logline="少年逆袭",
+        selling_points=["爽点密集", "升级流"],
+    )
+
+
+def test_build_context_includes_all_four_sources() -> None:
+    text = build_outline_context(
+        project=_project(),
+        foreshadow=[
+            ForeshadowLedgerView(
+                code="F1", title="神秘信物", status="OPEN", planted_at=3, expected_close_to=10
+            )
+        ],
+        characters=[CharacterView(name="主角", role="protagonist", motive="复仇")],
+        world_entities=[WorldEntityView(type="location", name="剑冢")],
+    )
+    assert "逆天剑帝" in text
+    assert "F1" in text and "神秘信物" in text
+    assert "回收窗口 ?-10" in text
+    assert "主角" in text
+    assert "剑冢" in text
+
+
+def test_build_context_is_deterministic_and_sorted() -> None:
+    project = _project()
+    fs = [
+        ForeshadowLedgerView(code="F2", title="b", status="OPEN"),
+        ForeshadowLedgerView(code="F1", title="a", status="OPEN"),
+    ]
+    a = build_outline_context(project=project, foreshadow=fs, characters=[], world_entities=[])
+    b = build_outline_context(
+        project=project, foreshadow=list(reversed(fs)), characters=[], world_entities=[]
+    )
+    assert a == b
+    # F1 排在 F2 前（按 code 升序）。
+    assert a.index("[F1]") < a.index("[F2]")
+
+
+def test_build_context_handles_empty_sources() -> None:
+    text = build_outline_context(
+        project=_project(), foreshadow=[], characters=[], world_entities=[]
+    )
+    assert "（无）" in text