fix(tts): use opus format and enable voice bubbles for feishu and whatsapp (#27366)

* fix(tts): use opus format and enable voice bubbles for feishu and whatsapp

Previously only Telegram received opus output and had `shouldVoice=true`.
Feishu and WhatsApp also support voice-bubble playback and require opus audio,
but were falling back to mp3 with `audioAsVoice=false`.

- Extract VOICE_BUBBLE_CHANNELS set (telegram, feishu, whatsapp)
- resolveOutputFormat: return TELEGRAM_OUTPUT (opus) for all voice-bubble channels
- shouldVoice: enable for all voice-bubble channels, not just telegram
- Update test to cover feishu and whatsapp cases

* Changelog: add TTS voice-bubble channel coverage note

---------

Co-authored-by: Ning Hu <ninghu@Nings-MacBook-Pro.local>
Co-authored-by: Tak Hoffman <781889+Takhoffman@users.noreply.github.com>

src/tts/tts.ts

@@ -480,8 +480,11 @@ export function setLastTtsAttempt(entry: TtsStatusEntry | undefined): void {
   lastTtsAttempt = entry;
 }
 
+/** Channels that require opus audio and support voice-bubble playback */
+const VOICE_BUBBLE_CHANNELS = new Set(["telegram", "feishu", "whatsapp"]);
+
 function resolveOutputFormat(channelId?: string | null) {
-  if (channelId === "telegram") {
+  if (channelId && VOICE_BUBBLE_CHANNELS.has(channelId)) {
     return TELEGRAM_OUTPUT;
   }
   return DEFAULT_OUTPUT;
@@ -911,7 +914,8 @@ export async function maybeApplyTtsToPayload(params: {
     };
 
     const channelId = resolveChannelId(params.channel);
-    const shouldVoice = channelId === "telegram" && result.voiceCompatible === true;
+    const shouldVoice =
+      channelId !== null && VOICE_BUBBLE_CHANNELS.has(channelId) && result.voiceCompatible === true;
     const finalPayload = {
       ...nextPayload,
       mediaUrl: result.audioPath,