Fix draft timer display drifting due to server-client clock skew

The countdown display used data.expiresAt (a server-side Unix timestamp)
subtracted from client Date.now(). When the server clock is ahead of the
client by ~2-3s (observed in production), the display inflated by that
delta — causing 2:02 instead of 2:00 on pick start, short-crediting the
chess clock increment, and the commissioner's adjust-time-bank dialog
disagreeing with the visible countdown.

Fix: replace all server expiresAt timestamps with a client-local expiry
computed from the server-provided timeRemaining integer
(Date.now() + timeRemaining * 1000). The skew then cancels algebraically:
server_remaining = server_expiresAt - pickMadeAt
                 = (client_schedule + Δ + bank*1000) - (client_pick + Δ)
                 = client_expiresAt - client_pick  ✓

Three sites updated: handleTimerPickStarted, handleDraftStateSync
(reconnect), and the initial useState seed from loader data.

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

app/hooks/useDraftSocketEvents.ts

@@ -121,7 +121,7 @@ export function useDraftSocketEvents({
     }) => {
       setCurrentPick(data.pickNumber);
       setTeamTimers((prev) => ({ ...prev, [data.teamId]: data.timeRemaining }));
-      setPickTimerExpiresAt({ teamId: data.teamId, expiresAt: data.expiresAt });
+      setPickTimerExpiresAt({ teamId: data.teamId, expiresAt: Date.now() + data.timeRemaining * 1000 });
       setIsOvernightPause(false);
       setOvernightResumesAt(null);
     };
@@ -248,8 +248,8 @@ export function useDraftSocketEvents({
           // so a reconnect after autopick fired doesn't briefly show a stale countdown.
           const now = Date.now();
           const activeTimer = data.timers.find((t) => t.expiresAt !== undefined && t.expiresAt > now);
-          if (activeTimer?.expiresAt) {
-            setPickTimerExpiresAt({ teamId: activeTimer.teamId, expiresAt: activeTimer.expiresAt });
+          if (activeTimer) {
+            setPickTimerExpiresAt({ teamId: activeTimer.teamId, expiresAt: now + activeTimer.timeRemaining * 1000 });
           } else {
             setPickTimerExpiresAt(null);
           }

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

@@ -111,6 +111,7 @@ export async function loader(args: Route.LoaderArgs) {
       getSeasonTimers(seasonId),
       getSeasonAutodraftSettings(seasonId),
     ]);
+  const loaderTimerNow = Date.now();
 
   const userQueue = userTeam
     ? await getTeamQueue(userTeam.id).catch((err) => {
@@ -177,6 +178,7 @@ export async function loader(args: Route.LoaderArgs) {
     userQueue,
     userWatchlist: userWatchlist.map((w) => w.participantId),
     timers,
+    loaderTimerNow,
     autodraftSettings,
     userAutodraftSettings,
     isCommissioner: !!isCommissioner,
@@ -196,6 +198,7 @@ export default function DraftRoom() {
     userQueue,
     userWatchlist,
     timers,
+    loaderTimerNow,
     autodraftSettings,
     userAutodraftSettings,
     isCommissioner,
@@ -500,11 +503,14 @@ export default function DraftRoom() {
   }, []);
   useEffect(() => () => { animationTimersRef.current.forEach(clearTimeout); }, []);
 
-  // Client-side countdown: updated every second from the server-provided expiresAt timestamp.
+  // Client-side countdown: always anchored to the client clock (not the server timestamp) to avoid skew.
   const [pickTimerExpiresAt, setPickTimerExpiresAt] = useState<{ teamId: string; expiresAt: number } | null>(() => {
-    // Seed from initial loader data if a timer is already running.
-    const active = timers.find((t) => t.picksExpiresAt && t.picksExpiresAt.getTime() > Date.now());
-    return active ? { teamId: active.teamId, expiresAt: active.picksExpiresAt?.getTime() ?? 0 } : null;
+    // 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;
+    const secondsRemaining = Math.ceil((active.picksExpiresAt.getTime() - loaderTimerNow) / 1000);
+    return { teamId: active.teamId, expiresAt: Date.now() + secondsRemaining * 1000 };
   });
 
   useEffect(() => {