feat(frontend): 写作工作台补齐三项——内容感知书名 / 上下文速查抽屉 / genre采集

写作工作台重构剩余 3 项（多 agent 并行构建各自新文件，主线统一集成）：

- WFW-5 内容感知书名（#6）：buildManuscriptExcerpt 取正文首尾摘录（硬上界控 token）；
  GeneratorRunner 加 manuscriptText，有 brief 字段时出现「用当前正文」按钮把摘录填入
  brief，让 book-title 等据正文反推。纯前端零后端；HITL——只填表单，生成仍需作者触发。
- WFW-6 上下文速查抽屉（#7）：ContextDrawer 视口无关右侧 slide-over，设定库/大纲完整
  只读速查 + 伏笔/规则/文风摘要跳链；底栏「速查」按钮触发。加法式、CONTEXT_DRAWER_ENABLED
  一键回滚、旧侧栏/全宽页路由全保留。
- WFW-7 genre 采集 + 无大纲降级：项目无题材时首次写章前弹 GenrePicker 采集（临时并入
  本次 directive 不落库）；chapters 为空时编辑器显式提示「尚无大纲，将按设定自由生成」。

各项 TDD：manuscriptExcerpt/useGenreGate/contextDrawer/useContextDrawer 共 32 新单测。
门禁全绿：vitest 629 / tsc / lint / build / coverage 95.43%。

apps/web/lib/workbench/useContextDrawer.test.ts

@@ -0,0 +1,165 @@
+// @vitest-environment jsdom
+import { act, renderHook, waitFor } from "@testing-library/react";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+import { useContextDrawerData } from "./useContextDrawer";
+
+// 后端客户端与 Toast 是 hook 的外部副作用边界，单测一律 mock。
+const get = vi.fn();
+const toast = vi.fn();
+vi.mock("@/lib/api/client", () => ({
+  api: { GET: (...a: unknown[]) => get(...a) },
+}));
+vi.mock("@/components/Toast", () => ({ useToast: () => toast }));
+
+const CODEX_PATH = "/projects/{project_id}/world_entities";
+const OUTLINE_PATH = "/projects/{project_id}/outline";
+
+// 按路径分流 codex / outline 两个端点的 mock 响应。
+function routeGet(
+  responses: {
+    codex?: unknown;
+    outline?: unknown;
+    codexReject?: boolean;
+    outlineReject?: boolean;
+  } = {},
+): void {
+  get.mockImplementation((path: string) => {
+    if (path === CODEX_PATH) {
+      if (responses.codexReject) return Promise.reject(new Error("net"));
+      return Promise.resolve(responses.codex ?? { data: null, error: null });
+    }
+    if (path === OUTLINE_PATH) {
+      if (responses.outlineReject) return Promise.reject(new Error("net"));
+      return Promise.resolve(responses.outline ?? { data: null, error: null });
+    }
+    return Promise.resolve({ data: null, error: null });
+  });
+}
+
+describe("useContextDrawerData", () => {
+  beforeEach(() => {
+    get.mockReset();
+    toast.mockReset();
+  });
+  afterEach(() => vi.clearAllMocks());
+
+  it("抽屉关闭时不发请求，两资源保持 idle", () => {
+    routeGet();
+    const { result } = renderHook(() =>
+      useContextDrawerData("p1", "codex", false),
+    );
+    expect(get).not.toHaveBeenCalled();
+    expect(result.current.codex.status).toBe("idle");
+    expect(result.current.outline.status).toBe("idle");
+  });
+
+  it("打开且在设定库 Tab：拉取并归组到 ready", async () => {
+    routeGet({
+      codex: {
+        data: {
+          world_entities: [
+            { type: "势力", name: "雾港议会", rules: [] },
+            { type: "地理", name: "北境", rules: [] },
+          ],
+        },
+        error: null,
+      },
+    });
+    const { result } = renderHook(() =>
+      useContextDrawerData("p1", "codex", true),
+    );
+    await waitFor(() => expect(result.current.codex.status).toBe("ready"));
+    expect(result.current.codex.data.map((g) => g.type)).toEqual([
+      "势力",
+      "地理",
+    ]);
+    expect(get).toHaveBeenCalledTimes(1);
+    expect(toast).not.toHaveBeenCalled();
+  });
+
+  it("打开且在大纲 Tab：拉取并按章号升序整形", async () => {
+    routeGet({
+      outline: {
+        data: {
+          chapters: [
+            { no: 2, volume: 1, beats: ["决战"], foreshadow_windows: [] },
+            { no: 1, volume: 1, beats: ["开场"], foreshadow_windows: [] },
+          ],
+        },
+        error: null,
+      },
+    });
+    const { result } = renderHook(() =>
+      useContextDrawerData("p1", "outline", true),
+    );
+    await waitFor(() => expect(result.current.outline.status).toBe("ready"));
+    expect(result.current.outline.data.map((r) => r.no)).toEqual([1, 2]);
+  });
+
+  it("data 为空时 ready 且为空数组", async () => {
+    routeGet({ codex: { data: { world_entities: null }, error: null } });
+    const { result } = renderHook(() =>
+      useContextDrawerData("p1", "codex", true),
+    );
+    await waitFor(() => expect(result.current.codex.status).toBe("ready"));
+    expect(result.current.codex.data).toEqual([]);
+  });
+
+  it("后端返回 error：error 态 + 错误 toast", async () => {
+    routeGet({ codex: { data: null, error: { detail: "boom" } } });
+    const { result } = renderHook(() =>
+      useContextDrawerData("p1", "codex", true),
+    );
+    await waitFor(() => expect(result.current.codex.status).toBe("error"));
+    expect(toast).toHaveBeenCalledWith(expect.any(String), "error");
+  });
+
+  it("请求抛异常：error 态 + 网络异常 toast", async () => {
+    routeGet({ codexReject: true });
+    const { result } = renderHook(() =>
+      useContextDrawerData("p1", "codex", true),
+    );
+    await waitFor(() => expect(result.current.codex.status).toBe("error"));
+    expect(toast).toHaveBeenCalledWith(
+      "设定库加载异常，请检查网络。",
+      "error",
+    );
+  });
+
+  it("已加载后切走再切回不重复拉取（缓存）", async () => {
+    routeGet({
+      codex: {
+        data: { world_entities: [{ type: "势力", name: "甲", rules: [] }] },
+        error: null,
+      },
+    });
+    const { result, rerender } = renderHook(
+      ({ tab }: { tab: "codex" | "outline" }) =>
+        useContextDrawerData("p1", tab, true),
+      { initialProps: { tab: "codex" } as { tab: "codex" | "outline" } },
+    );
+    await waitFor(() => expect(result.current.codex.status).toBe("ready"));
+    rerender({ tab: "outline" });
+    rerender({ tab: "codex" });
+    expect(get.mock.calls.filter((c) => c[0] === CODEX_PATH)).toHaveLength(1);
+  });
+
+  it("reloadCodex 在出错后可重试拉取", async () => {
+    routeGet({ codex: { data: null, error: { detail: "boom" } } });
+    const { result } = renderHook(() =>
+      useContextDrawerData("p1", "codex", true),
+    );
+    await waitFor(() => expect(result.current.codex.status).toBe("error"));
+
+    routeGet({
+      codex: {
+        data: { world_entities: [{ type: "势力", name: "甲", rules: [] }] },
+        error: null,
+      },
+    });
+    act(() => result.current.reloadCodex());
+    await waitFor(() => expect(result.current.codex.status).toBe("ready"));
+    expect(result.current.codex.data).toHaveLength(1);
+  });
+});