fix error line

src/components/ai-assistant/history.js

@@ -42,7 +42,7 @@ export function readHistory() {
     return list
       .filter((r) => r && r.id && Array.isArray(r.messages) && r.messages.length)
       .filter((r) => new Date(r.updatedAt || 0).getTime() >= cutoff)
-      .sort((a, b) => new Date(b.updatedAt || 0) - new Date(a.updatedAt || 0));
+      .sort((a, b) => new Date(b.updatedAt || 0).getTime() - new Date(a.updatedAt || 0).getTime());
   } catch {
     /* Corrupt or unavailable storage is an empty history, not an error the
        reader has to deal with. */