When a source is selected, a new card appears between the import action
controls and the progress panel showing all brands being imported from
that source as pill chips. Single-brand sources show just the name;
multi-brand sources show a count heading + all brand chips.
Styling: indigo pill chips with dark-mode support via
@media (prefers-color-scheme: dark). No external deps added.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
