优化：公屏叫号默认播放并移除声音控制

需求：服务端下发音频已验证可用，公屏无需再显示开启声音按钮和状态提示。

实现：移除声音控制组件与首次点击门槛，新叫号到达后直接播放内置音频队列。

验证：前端 65 项测试通过，生产构建通过。

web/src/components/AudioControl.tsx

@@ -1,37 +0,0 @@
-import type { RefObject } from "react";
-import type { AudioAnnouncementStatus } from "../hooks/useAudioAnnouncements";
-
-interface AudioControlProps {
-  audioRef: RefObject<HTMLAudioElement | null>;
-  status: AudioAnnouncementStatus;
-  onEnable: () => void;
-}
-
-export function AudioControl({ audioRef, status, onEnable }: AudioControlProps) {
-  return (
-    <>
-      <audio ref={audioRef} preload="auto" aria-hidden="true" />
-      {status === "ready" ? (
-        <aside className="speech-control speech-control--ready" role="status">
-          <strong>叫号声音已开启</strong>
-          <span>后续叫号将自动播报三次</span>
-        </aside>
-      ) : (
-        <aside className={`speech-control${status === "error" ? " speech-control--error" : ""}`} role="status">
-          <div>
-            <strong>{status === "error" ? "叫号声音开启失败" : "叫号声音尚未开启"}</strong>
-            <span>{status === "error" ? "请检查设备媒体音量后重试" : "请点击一次，之后将自动播报"}</span>
-          </div>
-          <button
-            className="button button--primary"
-            type="button"
-            disabled={status === "enabling"}
-            onClick={onEnable}
-          >
-            {status === "enabling" ? "正在开启叫号声音" : status === "error" ? "重新开启叫号声音" : "开启叫号声音"}
-          </button>
-        </aside>
-      )}
-    </>
-  );
-}