```

feat(game): add player cards and topbar styling for Chengdu Mahjong game

- Add new CSS classes for topbar layout including .topbar-left,
  .topbar-back-btn, .topbar-room-meta, .eyebrow, and .topbar-room-name
- Create dedicated player card components for each seat position
  (top, right, bottom, left)
- Refactor seatDecor computed property to use SeatPlayerCardModel
  interface with proper typing
- Replace inline player badge rendering with reusable player card
  components
- Update game header layout to use new topbar structure with
  back button and room metadata
- Adjust spacing and font sizes in game header elements
```

src/components/game/seat-player-card.ts

@@ -0,0 +1,9 @@
+export interface SeatPlayerCardModel {
+  avatar: string
+  name: string
+  money: string
+  dealer: boolean
+  isTurn: boolean
+  isOnline: boolean
+  missingSuitLabel: string
+}