Replace the close button and heading with fold/unfold controls that
collapse the panel to a slim right-edge tab showing the creature name
vertically, and add a pin button (xl+ viewports with creature loaded)
that opens the creature in a second left-side panel for simultaneous
reference. Fold state is respected on turn change. 19 acceptance tests.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>