feat(channels): add voice message support in TelegramAdapter (#3150)

Add handler for message:voice in Telegram channel adapter.
Voice messages are downloaded via Telegram Bot API and passed as
audio attachments in the Envelope, matching the existing pattern
for document handling.

This enables users to send voice messages through Telegram which
can then be processed by the model or transcription skills.

Co-authored-by: Teafey <Teafey@users.noreply.github.com>

packages/channels/telegram/src/TelegramAdapter.ts

@@ -155,6 +155,59 @@ export class TelegramChannel extends ChannelBase {
       });
     });
 
+    // Voice messages
+    this.bot.on('message:voice', async (ctx) => {
+      const msg = ctx.message;
+      const voice = msg.voice;
+      const fileName = `voice_${Date.now()}.ogg`;
+
+      const envelope = this.buildEnvelope(
+        msg,
+        msg.caption || '(voice message)',
+        msg.caption_entities,
+      );
+
+      try {
+        const file = await ctx.api.getFile(voice.file_id);
+        const fileUrl = this.getFileUrl(file.file_path!);
+        const resp = await fetch(fileUrl);
+        if (!resp.ok) throw new Error(`HTTP ${resp.status}`);
+        const buf = Buffer.from(await resp.arrayBuffer());
+
+        // Save to temp dir so the agent can read it via read-file tool
+        const dir = join(tmpdir(), 'channel-files', randomUUID());
+        mkdirSync(dir, { recursive: true });
+        const filePath = join(dir, fileName);
+        writeFileSync(filePath, buf);
+
+        envelope.text = msg.caption || '';
+        envelope.attachments = [
+          {
+            type: 'audio',
+            filePath,
+            mimeType: voice.mime_type || 'audio/ogg',
+            fileName,
+          },
+        ];
+      } catch (err) {
+        process.stderr.write(
+          `[Telegram:${this.name}] Failed to download voice message: ${err instanceof Error ? err.message : err}\n`,
+        );
+        envelope.text =
+          (msg.caption || '') +
+          `\n\n(User sent a voice message but download failed)`;
+      }
+
+      this.handleInbound(envelope).catch((err) => {
+        process.stderr.write(
+          `[Telegram:${this.name}] Error handling message: ${err}\n`,
+        );
+        ctx
+          .reply('Sorry, something went wrong processing your message.')
+          .catch(() => {});
+      });
+    });
+
     this.bot.start({ drop_pending_updates: true }).catch((err) => {
       process.stderr.write(
         `[Telegram:${this.name}] Bot launch error: ${err}\n`,