Fix TS error: narrow picksExpiresAt via optional chain guard

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/routes/leagues/$leagueId.draft.$seasonId.tsx

@@ -508,7 +508,7 @@ export default function DraftRoom() {
     // loaderTimerNow is server-side Date.now() — subtract from server expiresAt to get ms remaining
     // without skew, then re-anchor to client clock.
     const active = timers.find((t) => t.picksExpiresAt && t.picksExpiresAt.getTime() > loaderTimerNow);
-    if (!active) return null;
+    if (!active?.picksExpiresAt) return null;
     const secondsRemaining = Math.ceil((active.picksExpiresAt.getTime() - loaderTimerNow) / 1000);
     return { teamId: active.teamId, expiresAt: Date.now() + secondsRemaining * 1000 };
   });