fix(downloads): show — instead of 待整理 for unorganized external tasks (DL-2b)

Co-Authored-By: Claude Opus 5.5 <[email protected]>

apps/web/app/components/downloads/download-board.tsx

@@ -195,6 +195,7 @@ export function activeColumns(): DataColumn<DownloadBoardItem>[] {
 
 function OrganizeBadge({ t }: { t: DownloadBoardItem }) {
   const s = organizeState(t);
+  if (!s) return <span className="text-meta text-muted-foreground">—</span>;
   const badge = <StatusBadge tone={s.tone}>{s.label}</StatusBadge>;
   return (
     <div className="flex max-w-56 flex-col items-start gap-0.5">