fix: flip audio default to file (backward compat)

- Default: sendAudio (file with metadata) - preserves old behavior
- Opt-in: [[audio_as_voice]] tag for voice bubble

This is non-breaking - existing integrations keep working.

src/auto-reply/reply/audio-tags.ts

@@ -1,22 +1,23 @@
 /**
  * Extract audio mode tag from text.
- * Supports [[audio_as_file]] to send audio as file instead of voice bubble.
+ * Supports [[audio_as_voice]] to send audio as voice bubble instead of file.
+ * Default is file (preserves backward compatibility).
  */
 export function extractAudioTag(text?: string): {
   cleaned: string;
   audioAsVoice: boolean;
   hasTag: boolean;
 } {
-  if (!text) return { cleaned: "", audioAsVoice: true, hasTag: false };
+  if (!text) return { cleaned: "", audioAsVoice: false, hasTag: false };
   let cleaned = text;
-  let audioAsVoice = true; // default: voice bubble
+  let audioAsVoice = false; // default: audio file (backward compatible)
   let hasTag = false;
 
-  // [[audio_as_file]] -> send as file with metadata, not voice bubble
-  const fileMatch = cleaned.match(/\[\[audio_as_file\]\]/i);
-  if (fileMatch) {
-    cleaned = cleaned.replace(/\[\[audio_as_file\]\]/gi, " ");
-    audioAsVoice = false;
+  // [[audio_as_voice]] -> send as voice bubble (opt-in)
+  const voiceMatch = cleaned.match(/\[\[audio_as_voice\]\]/i);
+  if (voiceMatch) {
+    cleaned = cleaned.replace(/\[\[audio_as_voice\]\]/gi, " ");
+    audioAsVoice = true;
     hasTag = true;
   }
 

src/telegram/bot.ts

@@ -1250,12 +1250,14 @@ async function deliverReplies(params: {
           ...mediaParams,
         });
       } else if (kind === "audio") {
-        const useVoice = reply.audioAsVoice === true; // default false
+        const useVoice = reply.audioAsVoice === true; // default false (backward compatible)
         if (useVoice) {
+          // Voice message - displays as round playable bubble (opt-in via [[audio_as_voice]])
           await bot.api.sendVoice(chatId, file, {
             ...mediaParams,
           });
         } else {
+          // Audio file - displays with metadata (title, duration) - DEFAULT
           await bot.api.sendAudio(chatId, file, {
             ...mediaParams,
           });