Reopen rounds, file type buttons, checklist live-update

- Add reopenRound() to round engine (CLOSED → ACTIVE) with auto-pause of subsequent active rounds
- Add reopen endpoint to roundEngine router and UI button on round detail page
- Replace free-text MIME type input with toggle-only badge buttons in file requirements editor
- Enable refetchOnWindowFocus and shorter polling intervals for readiness checklist queries

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

src/app/(admin)/admin/rounds/[roundId]/page.tsx

@@ -76,6 +76,7 @@ import {
   Plus,
   Trash2,
   ArrowRight,
+  RotateCcw,
   X,
 } from 'lucide-react'
 import { RoundConfigForm } from '@/components/admin/competition/round-config-form'
@@ -159,22 +160,22 @@ export default function RoundDetailPage() {
   // ── Core data queries ──────────────────────────────────────────────────
   const { data: round, isLoading } = trpc.round.getById.useQuery(
     { id: roundId },
-    { refetchInterval: 30_000 },
+    { refetchInterval: 15_000, refetchOnWindowFocus: true },
   )
   const { data: projectStates } = trpc.roundEngine.getProjectStates.useQuery(
     { roundId },
-    { refetchInterval: 15_000 },
+    { refetchInterval: 10_000, refetchOnWindowFocus: true },
   )
 
   const competitionId = round?.competitionId ?? ''
 
   const { data: juryGroups } = trpc.juryGroup.list.useQuery(
     { competitionId },
-    { enabled: !!competitionId, refetchInterval: 30_000 },
+    { enabled: !!competitionId, refetchInterval: 30_000, refetchOnWindowFocus: true },
   )
   const { data: fileRequirements } = trpc.file.listRequirements.useQuery(
     { roundId },
-    { refetchInterval: 30_000 },
+    { refetchInterval: 15_000, refetchOnWindowFocus: true },
   )
 
   // Fetch awards linked to this round
@@ -223,6 +224,18 @@ export default function RoundDetailPage() {
     onError: (err) => toast.error(err.message),
   })
 
+  const reopenMutation = trpc.roundEngine.reopen.useMutation({
+    onSuccess: (data) => {
+      utils.round.getById.invalidate({ id: roundId })
+      utils.roundEngine.getProjectStates.invalidate({ roundId })
+      const msg = data.pausedRounds?.length
+        ? `Round reopened. Paused: ${data.pausedRounds.join(', ')}`
+        : 'Round reopened'
+      toast.success(msg)
+    },
+    onError: (err) => toast.error(err.message),
+  })
+
   const archiveMutation = trpc.roundEngine.archive.useMutation({
     onSuccess: () => {
       utils.round.getById.invalidate({ id: roundId })
@@ -268,7 +281,7 @@ export default function RoundDetailPage() {
     },
   })
 
-  const isTransitioning = activateMutation.isPending || closeMutation.isPending || archiveMutation.isPending
+  const isTransitioning = activateMutation.isPending || closeMutation.isPending || reopenMutation.isPending || archiveMutation.isPending
 
   const handleConfigChange = useCallback((newConfig: Record<string, unknown>) => {
     setConfig(newConfig)
@@ -437,11 +450,11 @@ export default function RoundDetailPage() {
                   {status === 'ROUND_CLOSED' && (
                     <>
                       <DropdownMenuItem
-                        onClick={() => activateMutation.mutate({ roundId })}
+                        onClick={() => reopenMutation.mutate({ roundId })}
                         disabled={isTransitioning}
                       >
                         <Play className="h-4 w-4 mr-2 text-emerald-600" />
-                        Reactivate Round
+                        Reopen Round
                       </DropdownMenuItem>
                       <DropdownMenuSeparator />
                       <DropdownMenuItem
@@ -775,6 +788,36 @@ export default function RoundDetailPage() {
                   </AlertDialog>
                 )}
 
+                {status === 'ROUND_CLOSED' && (
+                  <AlertDialog>
+                    <AlertDialogTrigger asChild>
+                      <button className="flex items-start gap-3 p-4 rounded-lg border hover:bg-muted/50 transition-colors text-left border-amber-200 bg-amber-50/50">
+                        <RotateCcw className="h-5 w-5 text-amber-600 mt-0.5 shrink-0" />
+                        <div>
+                          <p className="text-sm font-medium">Reopen Round</p>
+                          <p className="text-xs text-muted-foreground mt-0.5">
+                            Reactivate this round. Any subsequent active rounds will be paused.
+                          </p>
+                        </div>
+                      </button>
+                    </AlertDialogTrigger>
+                    <AlertDialogContent>
+                      <AlertDialogHeader>
+                        <AlertDialogTitle>Reopen this round?</AlertDialogTitle>
+                        <AlertDialogDescription>
+                          The round will become active again. Any rounds after this one that are currently active will be paused (closed) automatically.
+                        </AlertDialogDescription>
+                      </AlertDialogHeader>
+                      <AlertDialogFooter>
+                        <AlertDialogCancel>Cancel</AlertDialogCancel>
+                        <AlertDialogAction onClick={() => reopenMutation.mutate({ roundId })}>
+                          Reopen
+                        </AlertDialogAction>
+                      </AlertDialogFooter>
+                    </AlertDialogContent>
+                  </AlertDialog>
+                )}
+
                 {/* Assign projects */}
                 <Link href={poolLink}>
                   <button className="flex items-start gap-3 p-4 rounded-lg border hover:bg-muted/50 transition-colors text-left w-full">