fix(voice): enable TTS voice reply when streaming is active (#2322)

When streaming is enabled, the base adapter receives None from
_handle_message (already_sent=True) and cannot run auto-TTS for
voice input. The runner was unconditionally skipping voice input
TTS assuming the base adapter would handle it.

Now the runner takes over TTS responsibility when streaming has
already delivered the text response, so voice channel playback
works with both streaming on and off.

Streaming off behavior is unchanged (default already_sent=False
preserves the original code path exactly).

Co-authored-by: 0xbyt4 <35742124+0xbyt4@users.noreply.github.com>

gateway/run.py

@@ -2248,7 +2248,8 @@ class GatewayRunner:
             )
 
             # Auto voice reply: send TTS audio before the text response
-            if self._should_send_voice_reply(event, response, agent_messages):
+            _already_sent = bool(agent_result.get("already_sent"))
+            if self._should_send_voice_reply(event, response, agent_messages, already_sent=_already_sent):
                 await self._send_voice_reply(event, response)
 
             # If streaming already delivered the response, return None so
@@ -3054,6 +3055,7 @@ class GatewayRunner:
         event: MessageEvent,
         response: str,
         agent_messages: list,
+        already_sent: bool = False,
     ) -> bool:
         """Decide whether the runner should send a TTS voice reply.
 
@@ -3062,8 +3064,9 @@ class GatewayRunner:
         - response is empty or an error
         - agent already called text_to_speech tool (dedup)
         - voice input and base adapter auto-TTS already handled it (skip_double)
-          Exception: Discord voice channel — base play_tts is a no-op there,
-          so the runner must handle VC playback.
+          UNLESS streaming already consumed the response (already_sent=True),
+          in which case the base adapter won't have text for auto-TTS so the
+          runner must handle it.
         """
         if not response or response.startswith("Error:"):
             return False
@@ -3093,7 +3096,10 @@ class GatewayRunner:
 
         # Dedup: base adapter auto-TTS already handles voice input
         # (play_tts plays in VC when connected, so runner can skip).
-        if is_voice_input:
+        # When streaming already delivered the text (already_sent=True),
+        # the base adapter will receive None and can't run auto-TTS,
+        # so the runner must take over.
+        if is_voice_input and not already_sent:
             return False
 
         return True