Add schema reconciliation migration and file removal in bulk upload

Migration:
- Add standalone hasConflict index on ConflictOfInterest
- Ensure roundId is nullable on ConflictOfInterest
- Drop stale composite roundId_hasConflict index

Bulk upload:
- Add trash icon button to remove uploaded files
- Uses existing file.delete endpoint with audit logging

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

src/app/(admin)/admin/projects/bulk-upload/page.tsx

@@ -47,6 +47,7 @@ import {
   FileUp,
   AlertCircle,
   ExternalLink,
+  Trash2,
 } from 'lucide-react'
 import { cn, formatFileSize } from '@/lib/utils'
 import { Pagination } from '@/components/shared/pagination'
@@ -155,6 +156,26 @@ export default function BulkUploadPage() {
     [utils, refetch]
   )
 
+  // Delete a file
+  const deleteMutation = trpc.file.delete.useMutation({
+    onSuccess: () => {
+      toast.success('File removed')
+      refetch()
+    },
+    onError: (err) => {
+      toast.error(`Failed to remove file: ${err.message}`)
+    },
+  })
+
+  const handleDeleteFile = useCallback(
+    (fileId: string) => {
+      if (confirm('Remove this uploaded file?')) {
+        deleteMutation.mutate({ id: fileId })
+      }
+    },
+    [deleteMutation]
+  )
+
   const uploadMutation = trpc.file.adminUploadForRoundRequirement.useMutation()
 
   // Upload a single file for a project requirement
@@ -513,7 +534,20 @@ export default function BulkUploadPage() {
                                     </div>
                                   ) : req.file || uploadState?.status === 'complete' ? (
                                     <div className="flex flex-col items-center gap-1">
-                                      <CheckCircle2 className="h-4 w-4 text-green-600" />
+                                      <div className="flex items-center gap-1">
+                                        <CheckCircle2 className="h-4 w-4 text-green-600" />
+                                        {req.file && (
+                                          <button
+                                            type="button"
+                                            className="text-muted-foreground hover:text-destructive transition-colors cursor-pointer"
+                                            title="Remove file"
+                                            onClick={() => handleDeleteFile(req.file!.id)}
+                                            disabled={deleteMutation.isPending}
+                                          >
+                                            <Trash2 className="h-3 w-3" />
+                                          </button>
+                                        )}
+                                      </div>
                                       {req.file?.bucket && req.file?.objectKey ? (
                                         <button
                                           type="button"