Each card is a parent Sprite (white for face-up, blue for face-down) with
a Text2d child showing rank+suit (e.g. "AH", "10C", "KS"). Hearts and
diamonds render red; clubs and spades black. Face-down labels are hidden.
Tableau cards fan downward; other piles stack at the same position with a
small z-offset.
Sync runs in PostStartup for the initial deal and in Update after every
StateChangedEvent. To avoid a one-frame lag, downstream plugins run after
the new GameMutation system set.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>