fix: accept **kwargs in send_voice for Discord and Slack adapters

play_tts base class forwards metadata via **kwargs to send_voice,
but Discord and Slack adapters did not accept extra keyword arguments,
causing TypeError and silent message handling failure.

Also fix test_web_defaults to patch correct env var (WEB_UI_TOKEN).

gateway/platforms/discord.py

@@ -609,7 +609,7 @@ class DiscordAdapter(BasePlatformAdapter):
         audio_path: str,
         caption: Optional[str] = None,
         reply_to: Optional[str] = None,
-        metadata: Optional[Dict[str, Any]] = None,
+        **kwargs,
     ) -> SendResult:
         """Send audio as a Discord file attachment."""
         try:

gateway/platforms/slack.py

@@ -506,6 +506,7 @@ class SlackAdapter(BasePlatformAdapter):
         caption: Optional[str] = None,
         reply_to: Optional[str] = None,
         metadata: Optional[Dict[str, Any]] = None,
+        **kwargs,
     ) -> SendResult:
         """Send an audio file to Slack."""
         try:

tests/gateway/test_web.py

@@ -72,7 +72,7 @@ class TestConfigEnvOverrides(unittest.TestCase):
 
     @patch.dict(os.environ, {
         "WEB_UI_ENABLED": "true",
-        "WEB_TOKEN": "",
+        "WEB_UI_TOKEN": "",
     }, clear=False)
     def test_web_defaults(self):
         config = GatewayConfig()