feat(notebook): pre-select notebook source when notebook_id is in URL

frontend-web/src/pages/NotebookAIWritingPage.tsx

@@ -42,7 +42,10 @@ export default function NotebookAIWritingPage() {
 
       {/* 主体：AIWritingPage 完整组件，含 context providers */}
       <div className="flex-1 min-h-0 overflow-hidden">
-        <AIWritingPage hideAdvancedFields />
+        <AIWritingPage
+          hideAdvancedFields
+          initialNotebookId={notebookId ? Number(notebookId) : undefined}
+        />
       </div>
     </div>
   );