- Remove unused card_revealed broadcast + 1s asyncio.sleep in swap handler
(client never handled this message, causing pure dead wait before game_state)
- Defer swap-out (opacity:0) on hand cards to onStart callback so overlay
covers the card before hiding it — eliminates visual gap for all players
- Defer heldCardFloating visibility hide to onStart — held card stays visible
until animation overlay replaces it
- Thread onStart callback through animateUnifiedSwap → _runUnifiedSwap
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>