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/web/lib/outline/outline.test.ts

@@ -0,0 +1,63 @@
+import { describe, expect, it } from "vitest";
+
+import type {
+  ForeshadowWindowView,
+  OutlineChapterView,
+} from "@/lib/api/types";
+import {
+  groupByVolume,
+  isCloseWindow,
+  windowBadgeLabel,
+} from "./outline";
+
+const ch = (over: Partial<OutlineChapterView>): OutlineChapterView => ({
+  no: 1,
+  volume: 1,
+  beats: [],
+  foreshadow_windows: [],
+  ...over,
+});
+
+const win = (
+  over: Partial<ForeshadowWindowView>,
+): ForeshadowWindowView => ({ code: "F-012", ...over });
+
+describe("groupByVolume", () => {
+  it("groups by volume and sorts volumes and chapters ascending", () => {
+    const groups = groupByVolume([
+      ch({ no: 127, volume: 3 }),
+      ch({ no: 12, volume: 1 }),
+      ch({ no: 126, volume: 3 }),
+    ]);
+    expect(groups.map((g) => g.volume)).toEqual([1, 3]);
+    expect(groups[1]?.chapters.map((c) => c.no)).toEqual([126, 127]);
+  });
+
+  it("handles undefined", () => {
+    expect(groupByVolume(undefined)).toEqual([]);
+  });
+});
+
+describe("windowBadgeLabel", () => {
+  it("renders a range, half-open, or bare badge", () => {
+    expect(
+      windowBadgeLabel(win({ expected_close_from: 40, expected_close_to: 60 })),
+    ).toBe("⚑ F-012 (40-60)");
+    expect(windowBadgeLabel(win({ expected_close_to: 60 }))).toBe(
+      "⚑ F-012 (≤60)",
+    );
+    expect(windowBadgeLabel(win({ expected_close_from: 40 }))).toBe(
+      "⚑ F-012 (≥40)",
+    );
+    expect(windowBadgeLabel(win({}))).toBe("⚑ F-012");
+  });
+});
+
+describe("isCloseWindow", () => {
+  it("is true when chapter no is inside the recovery window", () => {
+    const w = win({ expected_close_from: 40, expected_close_to: 60 });
+    expect(isCloseWindow(ch({ no: 50 }), w)).toBe(true);
+    expect(isCloseWindow(ch({ no: 61 }), w)).toBe(false);
+    expect(isCloseWindow(ch({ no: 50 }), win({}))).toBe(false);
+  });
+});