The Pick flag on thumbnails, in Compare, in the loupe and on the Pick
button was the same outline as the button's idle state, so a pick was
hard to tell at a glance. A new filled pennant (`Icon::FlagPickFilled`)
marks a pick wherever a photo's own flag is shown; buttons, filters and
the reject flag keep their outlines.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011K1peyrh5MdZ6ttHkVq8Gh