feat(baccarat): 实现百家乐实时下注人数统计功能

- 新增 BaccaratPoolUpdated 事件，用于通过 WebSocket 广播实时下注数据更新
- 增加数据库迁移以在 baccarat_rounds 表中添加对应的下注人数统计字段
- 更新 BaccaratRound 模型以及 BaccaratController，支持实时下注统计更新与 WebSocket 事件分发
- 更新前端 chat.js 以及 baccarat-panel.blade.php，利用 Alpine.js 和 Echo 接收事件并动态渲染 "大"、"小"、"豹子" 的实时下注计数

app/Http/Controllers/BaccaratController.php

@@ -56,6 +56,9 @@ class BaccaratController extends Controller
                 'total_bet_big' => $round->total_bet_big,
                 'total_bet_small' => $round->total_bet_small,
                 'total_bet_triple' => $round->total_bet_triple,
+                'bet_count_big' => $round->bet_count_big,
+                'bet_count_small' => $round->bet_count_small,
+                'bet_count_triple' => $round->bet_count_triple,
                 'my_bet' => $myBet ? [
                     'bet_type' => $myBet->bet_type,
                     'amount' => $myBet->amount,
@@ -139,9 +142,14 @@ class BaccaratController extends Controller
 
             // 更新局次汇总统计
             $field = 'total_bet_'.$data['bet_type'];
+            $countField = 'bet_count_'.$data['bet_type'];
             $round->increment($field, $data['amount']);
+            $round->increment($countField);
             $round->increment('bet_count');
 
+            // 广播各选项的最新押注人数
+            event(new \App\Events\BaccaratPoolUpdated($round));
+
             $betLabel = match ($data['bet_type']) {
                 'big' => '大', 'small' => '小', default => '豹子'
             };