Use startTransition for delete refresh and fix filter updates

- DeleteItemButton now uses startTransition for router.refresh()
- ListDetailView re-applies filters when initialItems changes
- This ensures deleted items disappear after refresh completes
- Transition provides better React 18 concurrent rendering support

components/DeleteItemButton.tsx

@@ -1,6 +1,6 @@
 'use client'
 
-import { useState } from 'react'
+import { useState, useTransition } from 'react'
 import { useRouter } from 'next/navigation'
 import { deleteItem } from '@/lib/actions'
 import { Trash2 } from 'lucide-react'
@@ -17,18 +17,25 @@ export default function DeleteItemButton({ itemId, listId, variant = 'full' }: D
   const { showToast } = useToast()
   const [isDeleting, setIsDeleting] = useState(false)
   const [showConfirm, setShowConfirm] = useState(false)
+  const [isPending, startTransition] = useTransition()
 
   const handleDelete = async (e: React.MouseEvent) => {
     e.preventDefault()
     e.stopPropagation()
     setIsDeleting(true)
+    
     try {
       await deleteItem(itemId)
       showToast('Task deleted successfully', 'success')
+      
+      // Reset state immediately
       setShowConfirm(false)
       setIsDeleting(false)
-      // Always refresh to update the UI
-      router.refresh()
+      
+      // Use startTransition to refresh the route
+      startTransition(() => {
+        router.refresh()
+      })
     } catch (error) {
       console.error('Error deleting item:', error)
       showToast('Failed to delete task', 'error')
@@ -54,14 +61,14 @@ export default function DeleteItemButton({ itemId, listId, variant = 'full' }: D
       <div className="flex items-center gap-2">
         <button
           onClick={handleDelete}
-          disabled={isDeleting}
+          disabled={isDeleting || isPending}
           className="px-3 sm:px-4 py-2 sm:py-2.5 bg-red-500 hover:bg-red-600 active:bg-red-700 disabled:bg-red-300 text-white rounded-lg text-xs sm:text-sm transition-colors tap-target-sm font-medium"
         >
-          {isDeleting ? 'Deleting...' : 'Confirm'}
+          {isDeleting || isPending ? 'Deleting...' : 'Confirm'}
         </button>
         <button
           onClick={handleCancel}
-          disabled={isDeleting}
+          disabled={isDeleting || isPending}
           className="px-3 sm:px-4 py-2 sm:py-2.5 bg-gray-200 hover:bg-gray-300 active:bg-gray-400 text-gray-700 rounded-lg text-xs sm:text-sm transition-colors tap-target-sm font-medium"
         >
           Cancel