feat(server): synthetic root doc (#14794)

packages/backend/native/src/doc.rs

@@ -54,6 +54,12 @@ impl From<WorkspaceDocContent> for NativeWorkspaceDocContent {
   }
 }
 
+#[napi(object)]
+pub struct PublicDocMetaInput {
+  pub id: String,
+  pub title: Option<String>,
+}
+
 #[napi(object)]
 pub struct NativeBlockInfo {
   pub block_id: String,
@@ -254,6 +260,19 @@ pub fn add_doc_to_root_doc(root_doc_bin: Buffer, doc_id: String, title: Option<S
   Ok(Buffer::from(result))
 }
 
+#[napi]
+pub fn build_public_root_doc(root_doc_bin: Buffer, doc_metas: Vec<PublicDocMetaInput>) -> Result<Buffer> {
+  let metas = doc_metas
+    .iter()
+    .map(|meta| (meta.id.as_str(), meta.title.as_deref()))
+    .collect::<Vec<_>>();
+  let result = map_napi_err(
+    doc_parser::build_public_root_doc(&root_doc_bin, &metas),
+    Status::GenericFailure,
+  )?;
+  Ok(Buffer::from(result))
+}
+
 /// Updates a document title in the workspace root doc's meta.pages array.
 ///
 /// # Arguments