Position of this row in the filtered list.

Read-only from outside: PromptSearchPanel treats _options[0].index as the authority on which window is currently mounted, so an external write would silently defeat its staleness check. set_content is the only way to move a row.

Whether this row currently renders as selected.

Derived from the CSS class rather than mirrored in a field, so the two cannot drift.

Update the row in place during a panel rebuild.

Toggle the selected styling.

Post the click up to ChatInput.

Message sent when a prompt row is clicked.