feat(#1685): surface attachments in read_room + add download_file

hive-matrix-mcp/src/socket.rs

@@ -95,6 +95,11 @@ async fn dispatch(req: DaemonRequest, client: &Client) -> DaemonResponse {
         }
         DaemonRequest::ListRoomMembers { room } => handlers::list_room_members(client, &room).await,
         DaemonRequest::ReadRoom { room, limit } => handlers::read_room(client, &room, limit).await,
+        DaemonRequest::DownloadFile {
+            room,
+            event_id,
+            dest_path,
+        } => handlers::download_file(client, &room, &event_id, dest_path.as_deref()).await,
         DaemonRequest::UnreadCount => handlers::unread_count(client),
         DaemonRequest::UnreadSummary => handlers::unread_summary(client).await,
     }