feat: AI写作集成笔记来源，支持多文档多选检索

- 前端 AIWritingForm 新增笔记来源选择器（笔记本单选 + 文档多选 checkbox）
- AIWritingRequest 类型新增 noteSearchSpaceId / noteSourceIds 字段
- AIMaterial.sourceType 新增 notebook 类型
- useAIWritingStream startWriting 时自动获取 notebook_token 并携带笔记参数
- 后端 AIWritingState 新增 notebook_search_space_id / notebook_source_ids 字段
- researcher 节点新增 _search_notebook，解析 API 返回的 documents/chunks，
  每个 chunk 作为独立素材（source_type=notebook）混入素材包

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend-web/src/open-canvas/components/ai-writing/AIWritingForm.tsx

@@ -1,5 +1,5 @@
 import { useEffect, useMemo, useState } from 'react';
-import { PenLine } from 'lucide-react';
+import { BookOpen, PenLine, X } from 'lucide-react';
 
 import { Button } from '@/components/ui/button';
 import { Textarea } from '@/components/ui/textarea';
@@ -11,6 +11,7 @@ import {
   SelectValue,
 } from '@/components/ui/select';
 import { useModels } from '@/core/models/hooks';
+import { useStudioNotebooks, useNotebookSources } from '@/core/studio/hooks';
 
 import type { AIWritingRequest } from '../../types/ai-writing';
 import { useArticleTypes } from '../../hooks/useArticleTypes';
@@ -46,7 +47,13 @@ export function AIWritingForm({
   const [wordCountInput, setWordCountInput] = useState('800');
   const [strictMode, setStrictMode] = useState(false);
   const [modelName, setModelName] = useState('');
+  // 笔记来源：选中的 search_space_id 和多个 document_id
+  const [selectedNotebookId, setSelectedNotebookId] = useState<number | null>(null);
+  const [selectedDocumentIds, setSelectedDocumentIds] = useState<number[]>([]);
+
   const { models, isLoading: modelsLoading } = useModels();
+  const { notebooks, isLoading: notebooksLoading } = useStudioNotebooks();
+  const { sources, isLoading: sourcesLoading } = useNotebookSources(selectedNotebookId);
 
   const { articleTypes, loading: typesLoading, refresh: refreshTypes } = useArticleTypes();
 
@@ -98,6 +105,22 @@ export function AIWritingForm({
     }
   }
 
+  function handleNotebookChange(val: string) {
+    setSelectedNotebookId(val ? Number(val) : null);
+    setSelectedDocumentIds([]);
+  }
+
+  function clearNoteSelection() {
+    setSelectedNotebookId(null);
+    setSelectedDocumentIds([]);
+  }
+
+  function toggleDocument(docId: number) {
+    setSelectedDocumentIds((prev) =>
+      prev.includes(docId) ? prev.filter((id) => id !== docId) : [...prev, docId],
+    );
+  }
+
   function handleSubmit(e: React.FormEvent) {
     e.preventDefault();
     if (!intent.trim()) return;
@@ -112,6 +135,9 @@ export function AIWritingForm({
       keywordCount: DEFAULT_KEYWORD_COUNT,
       writingMode: hideAdvancedFields ? 'loose' : strictMode ? 'strict' : 'loose',
       modelName: selectedModel?.name || modelName || undefined,
+      noteSearchSpaceId: selectedNotebookId ?? undefined,
+      // 有勾选文档则传 document_id 列表，否则传空数组（搜整个笔记本）
+      noteSourceIds: selectedNotebookId != null ? selectedDocumentIds : undefined,
     });
   }
 
@@ -206,6 +232,82 @@ export function AIWritingForm({
           </Select>
         </div>
 
+        {/* 笔记来源（可选） */}
+        <div className="mt-4 rounded-xl border border-[#e8dedd] bg-[#f9f5f5] px-3 py-3 space-y-2">
+          <div className="flex items-center justify-between">
+            <div className="flex items-center gap-1.5">
+              <BookOpen className="size-3.5 text-[#8b6f6f]" />
+              <span className="text-sm font-semibold text-foreground">笔记来源（可选）</span>
+            </div>
+            {selectedNotebookId !== null && (
+              <button
+                type="button"
+                onClick={clearNoteSelection}
+                className="flex items-center gap-0.5 text-xs text-muted-foreground hover:text-foreground"
+              >
+                <X className="size-3" />
+                清除
+              </button>
+            )}
+          </div>
+
+          <Select
+            value={selectedNotebookId !== null ? String(selectedNotebookId) : ''}
+            onValueChange={handleNotebookChange}
+            disabled={disabled || notebooksLoading}
+          >
+            <SelectTrigger className={FIELD_TRIGGER_CLASS}>
+              <SelectValue placeholder={notebooksLoading ? '加载中…' : '选择笔记本（可不选）'} />
+            </SelectTrigger>
+            <SelectContent>
+              {notebooks.map((nb) => (
+                <SelectItem key={nb.id} value={String(nb.id)} className="text-sm">
+                  {nb.name}
+                </SelectItem>
+              ))}
+            </SelectContent>
+          </Select>
+
+          {selectedNotebookId !== null && (
+            <div className="space-y-1">
+              <p className="text-xs text-muted-foreground">
+                {sourcesLoading
+                  ? '文档加载中…'
+                  : sources.filter((s) => s.document?.id != null).length === 0
+                    ? '该笔记本暂无文档'
+                    : `选择文档（可多选；不选则搜索整个笔记本${selectedDocumentIds.length > 0 ? `，已选 ${selectedDocumentIds.length} 篇` : ''}）`}
+              </p>
+              {!sourcesLoading && (
+                <div className="max-h-40 overflow-y-auto rounded-lg border border-[#e8dedd] bg-white divide-y divide-[#f0e8e7]">
+                  {sources
+                    .filter((s) => s.document?.id != null)
+                    .map((s) => {
+                      const docId = s.document!.id;
+                      const checked = selectedDocumentIds.includes(docId);
+                      return (
+                        <label
+                          key={s.id}
+                          className="flex items-center gap-2 px-3 py-2 cursor-pointer hover:bg-[#f9f5f5] select-none"
+                        >
+                          <input
+                            type="checkbox"
+                            checked={checked}
+                            onChange={() => toggleDocument(docId)}
+                            disabled={disabled}
+                            className="size-3.5 shrink-0 accent-primary"
+                          />
+                          <span className="text-xs text-foreground truncate">
+                            {s.document?.title ?? `文档 ${docId}`}
+                          </span>
+                        </label>
+                      );
+                    })}
+                </div>
+              )}
+            </div>
+          )}
+        </div>
+
         <Button
           type="submit"
           disabled={disabled || !intent.trim()}

frontend-web/src/open-canvas/hooks/useAIWritingStream.ts

@@ -25,6 +25,8 @@ import { useCallback, useEffect, useMemo, useReducer, useRef } from 'react';
 import { useStream } from '@langchain/langgraph-sdk/react';
 
 import { getAPIClient } from '@/core/api';
+import { getStoredAuth } from '@/core/auth';
+import { fetchStudioToken } from '@/core/studio/api';
 
 import { useCanvasGraphContext } from '../contexts/CanvasGraphContext';
 import { saveAIWritingTranscript } from '../api/ai-writing-sessions';
@@ -720,6 +722,19 @@ export function useAIWriting() {
     if (state.status !== 'idle' && state.status !== 'done' && state.status !== 'error') return;
     dispatch({ type: 'start', request });
     try {
+      // 如果选择了笔记来源，获取 notebook token 用于后端检索
+      let notebookToken = '';
+      if (request.noteSearchSpaceId) {
+        const email = getStoredAuth()?.email ?? '';
+        if (email) {
+          try {
+            notebookToken = await fetchStudioToken(email);
+          } catch {
+            // 忽略 token 获取失败，后端会优雅降级
+          }
+        }
+      }
+
       await stream.submit(
         {
           user_intent: request.userIntent,
@@ -738,9 +753,16 @@ export function useAIWriting() {
           current_draft: null,
           review_result: null,
           last_user_intervention: null,
+          notebook_search_space_id: request.noteSearchSpaceId ?? null,
+          notebook_source_ids: request.noteSourceIds ?? [],
         } as Partial<AIWritingValues>,
         {
-          config: { configurable: { model_name: request.modelName ?? '' } } as Record<string, unknown>,
+          config: {
+            configurable: {
+              model_name: request.modelName ?? '',
+              ...(notebookToken ? { notebook_token: notebookToken } : {}),
+            },
+          } as Record<string, unknown>,
           streamMode: ['values', 'updates', 'custom', 'messages-tuple'],
         },
       );

frontend-web/src/open-canvas/types/ai-writing.ts

@@ -7,7 +7,7 @@ export interface AIMaterial {
   source: string;
   publishedAt: string;
   relevanceScore: number;
-  sourceType: 'internet' | 'intranet' | 'skill';
+  sourceType: 'internet' | 'intranet' | 'skill' | 'notebook';
   url?: string;
   recUuid?: string;
   // skill 类素材的元信息（skill_name / container_path / category / skill_full_content 等）
@@ -227,6 +227,10 @@ export interface AIWritingRequest {
   keywordCount: number;
   /** 写作模式：strict=严格依据素材 / loose=可结合通用知识（默认 loose） */
   writingMode: 'strict' | 'loose';
+  /** 笔记来源（可选）：笔记本 search_space_id */
+  noteSearchSpaceId?: number;
+  /** 笔记来源（可选）：笔记本内指定文档的 document_id 列表，空数组表示检索整个笔记本 */
+  noteSourceIds?: number[];
 }
 
 // ── 流式审核条目 ──────────────────────────────────────────────────────────────