feat(editor): save leptos island and page aggregate alignment progress

- switch main document flow toward leptos tiptap island host and generated runtime assets

- align page aggregate loading, page head single-source updates, and AI tool result recovery

- add tests and smoke scripts for title sync, AI route recovery, and editor host cutover

wolai-frontend/src/components/sidebar/preferred-sidebar-snapshot-context.tsx

@@ -0,0 +1,52 @@
+"use client";
+
+import { createContext, useContext, useMemo, type ReactNode } from "react";
+import type { DocumentRecord } from "@/lib/documents";
+import type { SidebarInitialData } from "@/components/sidebar/types";
+
+const PreferredSidebarSnapshotContext = createContext<SidebarInitialData | null>(null);
+
+interface PreferredSidebarSnapshotProviderProps {
+  data: SidebarInitialData;
+  children: ReactNode;
+}
+
+export function PreferredSidebarSnapshotProvider({
+  data,
+  children,
+}: PreferredSidebarSnapshotProviderProps) {
+  return (
+    <PreferredSidebarSnapshotContext.Provider value={data}>
+      {children}
+    </PreferredSidebarSnapshotContext.Provider>
+  );
+}
+
+export function useOptionalPreferredSidebarSnapshotData() {
+  return useContext(PreferredSidebarSnapshotContext);
+}
+
+export function usePreferredSidebarSnapshotData() {
+  const context = useOptionalPreferredSidebarSnapshotData();
+  if (!context) {
+    throw new Error("usePreferredSidebarSnapshotData 必须在 PreferredSidebarSnapshotProvider 中使用");
+  }
+  return context;
+}
+
+export function usePreferredSidebarDocument(documentId: string): DocumentRecord | null {
+  const snapshot = useOptionalPreferredSidebarSnapshotData();
+
+  return useMemo(() => {
+    if (!snapshot) {
+      return null;
+    }
+    return snapshot.documents.find((item) => item.id === documentId) ?? null;
+  }, [documentId, snapshot]);
+}
+
+export function usePreferredSidebarDocumentTitle(documentId: string): string | null {
+  const document = usePreferredSidebarDocument(documentId);
+  const title = document?.title?.trim();
+  return title ? title : null;
+}