feat(mobile): voice-first master replies with WeChat-style unread dot and 转文字

客户 2026-07-18 追加要求:师傅回复先以语音消息呈现(微信式),
未读带红点,点击播放,可选「转文字」展开全文;同时优化长文刷屏布局。

speech.ts:
- 播放控制器新增 preload(text):预合成 TTS 并写入源缓存(不播放),
  供语音气泡在首次点击前显示时长;失败返回 null
- 新增 measureAudioDuration(source):经 metadata 探测音频秒长(8s 超时兜底)

sop/index.vue:
- MasterMsg 增加 voiceStatus(preparing/ready/unavailable)/voiceDuration/
  unread/transcriptOpen
- 答案到达即后台预合成语音(说话内容=直接答案 answer 字段),
  就绪后气泡显示「🔊 N"」+未读红点;点击播放(再点停止,播放态变色),
  播放即清红点;「转文字」灰 chip 展开完整结构化内容
  (要点/提醒/引用/总结卡/反馈),微信同款交互
- TTS 不可用或答案为空时自动回退为纯文本气泡(播报按钮保留),
  训练概况等数据型回复直接文本呈现
- 布局优化:头部压缩,长文默认收进「转文字」,线程不再整段刷屏

验证:
- 本地:时长 13" 真实测得、红点播放后消失、转文字展开全文,3 张截图目检
- 生产冒烟:语音气泡+时长+红点+转文字 chip 全部就位
- H5 已发布(备份 h5-before-20260718045801)

说明:每条答案一次 TTS 合成调用(有缓存),试点量级成本可忽略;
练页会话化(批次二)将复用同一套语音气泡形态。

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

mobile-uni/src/services/speech.ts

@@ -210,10 +210,64 @@ export const createSpeechPlaybackController = (
     }
   };
 
+  /**
+   * Synthesize (and cache) audio for `text` without playing it, so a
+   * WeChat-style voice bubble can show duration before the first tap.
+   * Returns the audio source URL, or null when remote TTS is unavailable.
+   */
+  const preload = async (text: string): Promise<string | null> => {
+    const value = text.trim();
+    if (!value) return null;
+    const cached = sourceCache.get(value);
+    if (cached) return cached;
+    try {
+      const result = await synthesizeSpeech(value);
+      const source = result.inlineAudioUrl || result.audioUrl;
+      if (!source) return null;
+      sourceCache.set(value, source);
+      while (sourceCache.size > maxCachedSources) {
+        const oldestKey = sourceCache.keys().next().value as string | undefined;
+        if (!oldestKey) break;
+        sourceCache.delete(oldestKey);
+      }
+      return source;
+    } catch {
+      return null;
+    }
+  };
+
   const destroy = () => {
     stop();
     sourceCache.clear();
   };
 
-  return { toggle, stop, destroy };
+  return { toggle, stop, destroy, preload };
 };
+
+export const measureAudioDuration = (source: string): Promise<number | null> =>
+  new Promise((resolve) => {
+    if (typeof Audio === 'undefined') {
+      resolve(null);
+      return;
+    }
+    const probe = new Audio();
+    let settled = false;
+    const finish = (value: number | null) => {
+      if (settled) return;
+      settled = true;
+      probe.src = '';
+      resolve(value);
+    };
+    const timer = setTimeout(() => finish(null), 8000);
+    probe.preload = 'metadata';
+    probe.onloadedmetadata = () => {
+      clearTimeout(timer);
+      const duration = probe.duration;
+      finish(Number.isFinite(duration) && duration > 0 ? Math.max(1, Math.round(duration)) : null);
+    };
+    probe.onerror = () => {
+      clearTimeout(timer);
+      finish(null);
+    };
+    probe.src = source;
+  });