Add delete button for draft rounds with confirmation dialog

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

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

@@ -16,6 +16,17 @@ import { Badge } from '@/components/ui/badge'
 import { Skeleton } from '@/components/ui/skeleton'
 import { Progress } from '@/components/ui/progress'
 import { Separator } from '@/components/ui/separator'
+import {
+  AlertDialog,
+  AlertDialogAction,
+  AlertDialogCancel,
+  AlertDialogContent,
+  AlertDialogDescription,
+  AlertDialogFooter,
+  AlertDialogHeader,
+  AlertDialogTitle,
+  AlertDialogTrigger,
+} from '@/components/ui/alert-dialog'
 import {
   ArrowLeft,
   Edit,
@@ -31,7 +42,10 @@ import {
   BarChart3,
   Upload,
   Filter,
+  Trash2,
+  Loader2,
 } from 'lucide-react'
+import { toast } from 'sonner'
 import { format, formatDistanceToNow, isPast, isFuture } from 'date-fns'
 
 interface PageProps {
@@ -50,6 +64,15 @@ function RoundDetailContent({ roundId }: { roundId: string }) {
       utils.round.get.invalidate({ id: roundId })
     },
   })
+  const deleteRound = trpc.round.delete.useMutation({
+    onSuccess: () => {
+      toast.success('Round deleted')
+      router.push('/admin/rounds')
+    },
+    onError: () => {
+      toast.error('Failed to delete round')
+    },
+  })
 
   if (isLoading) {
     return <RoundDetailSkeleton />
@@ -162,6 +185,43 @@ function RoundDetailContent({ roundId }: { roundId: string }) {
               Close Round
             </Button>
           )}
+          {round.status === 'DRAFT' && (
+            <AlertDialog>
+              <AlertDialogTrigger asChild>
+                <Button variant="destructive">
+                  <Trash2 className="mr-2 h-4 w-4" />
+                  Delete
+                </Button>
+              </AlertDialogTrigger>
+              <AlertDialogContent>
+                <AlertDialogHeader>
+                  <AlertDialogTitle>Delete Round</AlertDialogTitle>
+                  <AlertDialogDescription>
+                    This will permanently delete &ldquo;{round.name}&rdquo; and all
+                    associated projects, assignments, and evaluations. This action
+                    cannot be undone.
+                  </AlertDialogDescription>
+                </AlertDialogHeader>
+                <AlertDialogFooter>
+                  <AlertDialogCancel>Cancel</AlertDialogCancel>
+                  <AlertDialogAction
+                    onClick={() => deleteRound.mutate({ id: round.id })}
+                    disabled={deleteRound.isPending}
+                    className="bg-destructive text-destructive-foreground hover:bg-destructive/90"
+                  >
+                    {deleteRound.isPending ? (
+                      <>
+                        <Loader2 className="mr-2 h-4 w-4 animate-spin" />
+                        Deleting...
+                      </>
+                    ) : (
+                      'Delete Round'
+                    )}
+                  </AlertDialogAction>
+                </AlertDialogFooter>
+              </AlertDialogContent>
+            </AlertDialog>
+          )}
         </div>
       </div>