Fix O(n²) lookup, memoize components and callbacks in QueueSection

- Build a participantMap (Map<id, participant>) with useMemo so each
  queue item lookup is O(1) instead of O(n) per render
- Memoize queueIds array for SortableContext to avoid churn
- Wrap handleDragEnd in useCallback so DndContext gets a stable reference
- Wrap SortableQueueItem in memo so it skips re-renders when props haven't
  changed (important since the parent re-renders every second during a
  live draft from timer-update socket events)
- Pass onRemoveFromQueue and onMakePick directly as props instead of
  creating new arrow functions per item per render; SortableQueueItem
  now calls them with the relevant id itself

https://claude.ai/code/session_01HPtNkL5m9xhYgtzWaGViSC

app/components/draft/QueueSection.tsx

@@ -1,4 +1,4 @@
-import { memo } from "react";
+import { memo, useCallback, useMemo } from "react";
 import { GripVertical } from "lucide-react";
 import { Button } from "~/components/ui/button";
 import { Badge } from "~/components/ui/badge";
@@ -47,7 +47,7 @@ interface QueueSectionProps {
 }
 
 // Sortable queue item component
-function SortableQueueItem({
+const SortableQueueItem = memo(function SortableQueueItem({
   item,
   index,
   participantName,
@@ -61,8 +61,8 @@ function SortableQueueItem({
   participantName: string;
   sportName?: string;
   canPick: boolean;
-  onRemove: () => void;
+  onRemove: (queueId: string) => void;
-  onDraft?: () => void;
+  onDraft?: (participantId: string) => void;
 }) {
   const {
     attributes,
@@ -109,7 +109,7 @@ function SortableQueueItem({
             variant="default"
             size="sm"
             className="h-7 text-xs bg-electric text-background hover:bg-electric/90"
-            onClick={onDraft}
+            onClick={() => onDraft(item.participantId)}
           >
             Draft
           </Button>
@@ -118,7 +118,7 @@ function SortableQueueItem({
           variant="ghost"
           size="icon"
           className="h-7 w-7 text-destructive hover:text-destructive hover:bg-destructive/10"
-          onClick={onRemove}
+          onClick={() => onRemove(item.id)}
           title="Remove from queue"
         >
           <span className="text-lg">×</span>
@@ -126,7 +126,7 @@ function SortableQueueItem({
       </div>
     </div>
   );
-}
+});
 
 export const QueueSection = memo(function QueueSection({
   queue,
@@ -150,18 +150,25 @@ export const QueueSection = memo(function QueueSection({
     })
   );
 
-  const handleDragEnd = (event: DragEndEvent) => {
+  const participantMap = useMemo(
-    const { active, over } = event;
+    () => new Map(availableParticipants.map((p) => [p.id, p])),
+    [availableParticipants]
+  );
 
-    if (over && active.id !== over.id) {
+  const queueIds = useMemo(() => queue.map((item) => item.id), [queue]);
-      const oldIndex = queue.findIndex((item) => item.id === active.id);
-      const newIndex = queue.findIndex((item) => item.id === over.id);
 
-      const reorderedQueue = arrayMove(queue, oldIndex, newIndex);
+  const handleDragEnd = useCallback(
-      const participantIds = reorderedQueue.map((item) => item.participantId);
+    (event: DragEndEvent) => {
-      onReorder(participantIds);
+      const { active, over } = event;
-    }
+      if (over && active.id !== over.id) {
-  };
+        const oldIndex = queue.findIndex((item) => item.id === active.id);
+        const newIndex = queue.findIndex((item) => item.id === over.id);
+        const reorderedQueue = arrayMove(queue, oldIndex, newIndex);
+        onReorder(reorderedQueue.map((item) => item.participantId));
+      }
+    },
+    [queue, onReorder]
+  );
 
   return (
     <div className="p-4">
@@ -177,24 +184,22 @@ export const QueueSection = memo(function QueueSection({
           onDragEnd={handleDragEnd}
         >
           <SortableContext
-            items={queue.map((item) => item.id)}
+            items={queueIds}
             strategy={verticalListSortingStrategy}
           >
             <div className="space-y-1.5 mb-4">
               {queue.map((item, index) => {
-                const participant = availableParticipants.find(
+                const participant = participantMap.get(item.participantId);
-                  (p) => p.id === item.participantId
-                );
                 return (
                   <SortableQueueItem
                     key={item.id}
                     item={item}
                     index={index}
-                    participantName={participant?.name || "Unknown"}
+                    participantName={participant?.name ?? "Unknown"}
                     sportName={participant?.sport.name}
                     canPick={canPick}
-                    onRemove={() => onRemoveFromQueue(item.id)}
+                    onRemove={onRemoveFromQueue}
-                    onDraft={onMakePick ? () => onMakePick(item.participantId) : undefined}
+                    onDraft={onMakePick}
                   />
                 );
               })}