app: Make action column sticky on search results table

The ellipsis menu was hidden when the table exceeded viewport width.
Adding sticky positioning keeps the action column visible at the
right edge regardless of horizontal scroll position.

Author: jhf

app/src/app/search/components/statistical-unit-table-header.tsx

@@ -239,7 +239,7 @@ export function StatisticalUnitTableHeader({
               );
           }
         })}
-        <TableHead />
+        <TableHead className="sticky right-0 bg-gray-50" />
       </TableRow>
     </TableHeader>
   );

app/src/app/search/components/statistical-unit-table-row.tsx

@@ -524,7 +524,7 @@ export const StatisticalUnitTableRow = ({
             );
         }
       })}
-      <TableCell key="column-action" className="py-2 p-1 text-right">
+      <TableCell key="column-action" className="py-2 p-1 text-right sticky right-0 bg-white">
         <SearchResultTableRowDropdownMenu unit={unit} />
       </TableCell>
     </TableRow>