fix(audit-wave-9): standardize on Sheet for previews; doctrine in CLAUDE.md

Swap the one outlier (client-interests-tab.tsx) from Vaul Drawer to
Sheet side=right so every detail-preview surface uses the same
primitive. Document the doctrine: Sheet for side panels on both desktop
and mobile; Vaul Drawer reserved for mobile-only bottom-sheet UX
(currently just MoreSheet).

Closes ui/ux M11.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/interests/interest-documents-tab.tsx

@@ -13,6 +13,7 @@ import { FilePreviewDialog } from '@/components/files/file-preview-dialog';
 import { PermissionGate } from '@/components/shared/permission-gate';
 import { usePaginatedQuery } from '@/hooks/use-paginated-query';
 import { useRealtimeInvalidation } from '@/hooks/use-realtime-invalidation';
+import { useConfirmation } from '@/hooks/use-confirmation';
 import { apiFetch } from '@/lib/api/client';
 
 interface InterestDocumentsTabProps {
@@ -35,6 +36,7 @@ export function InterestDocumentsTab({ interestId }: InterestDocumentsTabProps)
   const queryClient = useQueryClient();
   const [eoiDialogOpen, setEoiDialogOpen] = useState(false);
   const [previewFile, setPreviewFile] = useState<FileRow | null>(null);
+  const { confirm, dialog: confirmDialog } = useConfirmation();
 
   const { data: interest } = useQuery<InterestData>({
     queryKey: ['interests', interestId],
@@ -77,7 +79,12 @@ export function InterestDocumentsTab({ interestId }: InterestDocumentsTabProps)
   };
 
   const handleDelete = async (file: FileRow) => {
-    if (!confirm(`Delete "${file.filename}"? This cannot be undone.`)) return;
+    const ok = await confirm({
+      title: 'Delete file',
+      description: `Delete "${file.filename}"? This cannot be undone.`,
+      confirmLabel: 'Delete',
+    });
+    if (!ok) return;
     try {
       await apiFetch(`/api/v1/files/${file.id}`, { method: 'DELETE' });
       queryClient.invalidateQueries({ queryKey: filesQueryKey });
@@ -167,6 +174,7 @@ export function InterestDocumentsTab({ interestId }: InterestDocumentsTabProps)
         fileName={previewFile?.filename}
         mimeType={previewFile?.mimeType ?? undefined}
       />
+      {confirmDialog}
     </div>
   );
 }