fix: harden upload resilience and contracts

components/upload/FolderCard.tsx

@@ -1,7 +1,7 @@
 import dynamic from 'next/dynamic'
 import type { FolderEntry } from '@/lib/client-types'
 import { formatBytes } from '@/lib/format-bytes'
-import { SpinnerIcon, CheckIcon, XIcon, ChevronIcon } from '@/components/ui/icons'
+import { SpinnerIcon, CheckIcon, XIcon, ChevronIcon, WarningIcon } from '@/components/ui/icons'
 import DriveStatusLine from './DriveStatusLine'
 import WarningBanner from './WarningBanner'
 
@@ -63,6 +63,13 @@ export default function FolderCard({ entry, index, onToggleViewer, onRemove }: F
             <DriveStatusLine driveStatus={entry.driveStatus} driveError={entry.driveError} />
           )}
 
+          {entry.uploadWarning && (
+            <div className="mt-1.5 flex items-start gap-1.5 text-xs text-yellow-400">
+              <WarningIcon className="mt-0.5 h-3.5 w-3.5 shrink-0" />
+              <span className="line-clamp-2">{entry.uploadWarning}</span>
+            </div>
+          )}
+
           {entry.status === 'uploading' && (
             <div className="mt-1.5 w-full h-1 bg-black-700 rounded-full overflow-hidden">
               <div