fix(listview): fix search input clipping and match antd option height

Remove overflow:hidden from PanelContainer so the Input focus ring
is not clipped at the panel boundary.

Set OptionItem line-height to theme.lineHeight and derive the vertical
padding from antd's exact formula (controlHeight - fontSize * lineHeight) / 2,
matching the height of antd Select dropdown options in Explore.

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