feat(game): 添加当前回合座位高亮功能

- 计算当前回合座位标识符
- 将活动位置传递给风向指示器组件
- 实现回合座位视觉反馈机制

src/views/ChengduGamePage.vue

@@ -294,6 +294,11 @@ const seatWinds = computed<Record<SeatKey, string>>(() => {
   return result
 })
 
+const currentTurnSeat = computed<SeatKey | ''>(() => {
+  const turnSeat = seatViews.value.find((seat) => seat.isTurn)
+  return turnSeat?.key ?? ''
+})
+
 const currentPhaseText = computed(() => {
   const map: Record<string, string> = {
     waiting: '等待中',
@@ -2714,7 +2719,7 @@ onBeforeUnmount(() => {
 <!--            <span>{{ seatDecor.right.missingSuitLabel }}</span>-->
 <!--          </div>-->
 
-          <WindSquare class="center-wind-square" :seat-winds="seatWinds"/>
+          <WindSquare class="center-wind-square" :seat-winds="seatWinds" :active-position="currentTurnSeat"/>
 
           <div v-if="showWaitingOwnerTip" class="waiting-owner-tip">
             <span>等待房主开始游戏</span>