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.ts

@@ -0,0 +1,145 @@
+"use client";
+
+import { useEffect, useRef, useState } from "react";
+
+import { api } from "@/lib/api/client";
+import { useToast } from "@/components/Toast";
+import {
+  toCodexGroups,
+  toOutlineRows,
+  type CodexGroup,
+  type ContextTabKey,
+  type OutlineRow,
+} from "./contextDrawer";
+
+// 速查抽屉的数据层：抽屉打开且切到对应 Tab 时【懒加载】设定库 / 大纲（只读，绝不写库）。
+// 加载成功后缓存（切走再切回不重复拉）；项目切换清缓存；失败可 reload 重试。
+
+export type ResourceStatus = "idle" | "loading" | "ready" | "error";
+
+export interface ContextResource<T> {
+  status: ResourceStatus;
+  data: T;
+}
+
+export interface UseContextDrawerData {
+  codex: ContextResource<CodexGroup[]>;
+  outline: ContextResource<OutlineRow[]>;
+  reloadCodex: () => void;
+  reloadOutline: () => void;
+}
+
+const CODEX_PATH = "/projects/{project_id}/world_entities" as const;
+const OUTLINE_PATH = "/projects/{project_id}/outline" as const;
+const EMPTY_CODEX: CodexGroup[] = [];
+const EMPTY_OUTLINE: OutlineRow[] = [];
+
+export function useContextDrawerData(
+  projectId: string,
+  activeTab: ContextTabKey,
+  open: boolean,
+): UseContextDrawerData {
+  const [codex, setCodex] = useState<ContextResource<CodexGroup[]>>({
+    status: "idle",
+    data: EMPTY_CODEX,
+  });
+  const [outline, setOutline] = useState<ContextResource<OutlineRow[]>>({
+    status: "idle",
+    data: EMPTY_OUTLINE,
+  });
+  const toast = useToast();
+  // 单飞哨兵：已发起过请求就不再重复（成功缓存 / 在途去重）；出错时重置以允许重试。
+  const codexReqRef = useRef(false);
+  const outlineReqRef = useRef(false);
+  // reload 触发器：自增即重新拉取（配合把 req 哨兵复位）。
+  const [codexNonce, setCodexNonce] = useState(0);
+  const [outlineNonce, setOutlineNonce] = useState(0);
+
+  // 项目切换 → 清缓存 + 复位哨兵，允许对新项目重新拉取。声明在拉取 effect 之前，
+  // 保证同一次提交里先复位、后续 effect 才据此触发。
+  useEffect(() => {
+    codexReqRef.current = false;
+    outlineReqRef.current = false;
+    setCodex({ status: "idle", data: EMPTY_CODEX });
+    setOutline({ status: "idle", data: EMPTY_OUTLINE });
+  }, [projectId]);
+
+  useEffect(() => {
+    if (!open || activeTab !== "codex" || codexReqRef.current) return;
+    codexReqRef.current = true;
+    let cancelled = false;
+    setCodex({ status: "loading", data: EMPTY_CODEX });
+    void (async () => {
+      try {
+        const { data, error } = await api.GET(CODEX_PATH, {
+          params: { path: { project_id: projectId } },
+        });
+        if (cancelled) return;
+        if (error || !data) {
+          codexReqRef.current = false;
+          setCodex({ status: "error", data: EMPTY_CODEX });
+          toast("设定库加载失败，请重试。", "error");
+          return;
+        }
+        setCodex({
+          status: "ready",
+          data: toCodexGroups(data.world_entities ?? []),
+        });
+      } catch {
+        if (cancelled) return;
+        codexReqRef.current = false;
+        setCodex({ status: "error", data: EMPTY_CODEX });
+        toast("设定库加载异常，请检查网络。", "error");
+      }
+    })();
+    return () => {
+      cancelled = true;
+    };
+  }, [open, activeTab, projectId, codexNonce, toast]);
+
+  useEffect(() => {
+    if (!open || activeTab !== "outline" || outlineReqRef.current) return;
+    outlineReqRef.current = true;
+    let cancelled = false;
+    setOutline({ status: "loading", data: EMPTY_OUTLINE });
+    void (async () => {
+      try {
+        const { data, error } = await api.GET(OUTLINE_PATH, {
+          params: { path: { project_id: projectId } },
+        });
+        if (cancelled) return;
+        if (error || !data) {
+          outlineReqRef.current = false;
+          setOutline({ status: "error", data: EMPTY_OUTLINE });
+          toast("大纲加载失败，请重试。", "error");
+          return;
+        }
+        setOutline({
+          status: "ready",
+          data: toOutlineRows(data.chapters ?? []),
+        });
+      } catch {
+        if (cancelled) return;
+        outlineReqRef.current = false;
+        setOutline({ status: "error", data: EMPTY_OUTLINE });
+        toast("大纲加载异常，请检查网络。", "error");
+      }
+    })();
+    return () => {
+      cancelled = true;
+    };
+  }, [open, activeTab, projectId, outlineNonce, toast]);
+
+  const reloadCodex = (): void => {
+    codexReqRef.current = false;
+    setCodex({ status: "idle", data: EMPTY_CODEX });
+    setCodexNonce((n) => n + 1);
+  };
+  const reloadOutline = (): void => {
+    outlineReqRef.current = false;
+    setOutline({ status: "idle", data: EMPTY_OUTLINE });
+    setOutlineNonce((n) => n + 1);
+  };
+
+  return { codex, outline, reloadCodex, reloadOutline };
+}