Wire MoveDrawer into GameScreen and switch breakpoint to md
Mobile (<768px) now uses the MoveDrawerPanel triggered from the bottom
PlayerBar; desktop (>=768px) keeps the side-by-side sidebar layout.
Outer padding reduced to p-2 on mobile so the board reclaims ~16px of
horizontal space on small phones. Drawer auto-closes when activeGame.id
changes to avoid a stale-open state across games.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>