Switch to chips-only play: real cards at the table, winners picked on screen

- Remove the deck, hole cards, board, hand evaluator and reveal logic
  (cards are dealt physically; the site only tracks bets, pots and stacks)
- Showdown now waits for a winner per pot (main/side), chosen by a player
  still in the hand or the host; multiple winners split the pot
- All-in with no further betting goes straight to showdown
- Remove the 30s action clock / auto sit-out (everyone is at the same table)
- UI: winner picker panel (main winner auto-fills side pots), compact table

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

public/assets/common.js

@@ -92,6 +92,7 @@
     FLOP: 'FLOP',
     TURN: 'TURN',
     RIVER: 'RIVER',
+    SHOWDOWN: 'SHOWDOWN',
     FINISHING: 'FINISHING',
   };