fix(listview): search input contained within dropdown panel

Wrap Input in SearchRow with horizontal padding instead of margins on
.ant-input-affix-wrapper. width:100% + margin overflowed the container;
padding on a wrapper div keeps the input fully inside. Restore
overflow:hidden (needed for borderRadiusLG clipping) — it no longer
clips the input since the wrapper contains it correctly.

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