Wrap the mobile person panel in StammbaumBottomSheet: drag-handle grip with
swipe-down-to-dismiss (≥80px), full-screen backdrop button for tap-outside
dismiss, role=dialog + aria-label, focus trap, and Escape (NFR-A11Y-004).
Pan/zoom state is untouched by open/close (US-PANEL-001/002).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
