feat: 添加实时广播功能，支持风险预警、玩法切换和赔率更新，增强大厅公共频道的广播能力

app/Events/PlayToggleBroadcast.php

@@ -0,0 +1,62 @@
+<?php
+
+namespace App\Events;
+
+use Illuminate\Broadcasting\Channel;
+use Illuminate\Queue\SerializesModels;
+use Illuminate\Foundation\Events\Dispatchable;
+use Illuminate\Broadcasting\InteractsWithSockets;
+use Illuminate\Contracts\Broadcasting\ShouldBroadcastNow;
+
+/**
+ * 界面文档 §2.1：`play.toggle` —— 玩法开关变更推送。
+ *
+ * 触发时机：后台开启或关闭某玩法时。
+ * 前端处理：玩法列显示/隐藏或置灰/启用。
+ */
+final class PlayToggleBroadcast implements ShouldBroadcastNow
+{
+    use Dispatchable, InteractsWithSockets, SerializesModels;
+
+    /**
+     * @param  string  $playCode  玩法代码（如 straight_4d, box_2d 等）
+     * @param  bool  $enabled  是否启用
+     * @param  string|null  $reason  变更原因（可选）
+     * @param  int  $emittedAtMs  发送时间戳（毫秒）
+     */
+    public function __construct(
+        public readonly string $playCode,
+        public readonly bool $enabled,
+        public readonly ?string $reason,
+        public readonly int $emittedAtMs,
+    ) {}
+
+    /**
+     * 公共频道，所有在大厅的玩家都能收到。
+     *
+     * @return array<int, Channel>
+     */
+    public function broadcastOn(): array
+    {
+        return [new Channel('lottery-hall')];
+    }
+
+    public function broadcastAs(): string
+    {
+        return 'play.toggle';
+    }
+
+    /**
+     * @return array{play_code: string, enabled: bool, reason: string|null, action: string, emitted_at_ms: int}
+     */
+    public function broadcastWith(): array
+    {
+        return [
+            'play_code' => $this->playCode,
+            'enabled' => $this->enabled,
+            'reason' => $this->reason,
+            'action' => $this->enabled ? 'enabled' : 'disabled',
+            'emitted_at_ms' => $this->emittedAtMs,
+        ];
+    }
+}