feat: add Inworld TTS provider support (#420)

* Add Inworld TTS provider integration

* chore: move from HTTP Service to Websocket Service

---------

Co-authored-by: Abhishek Kumar <abhishek@a6k.me>

api/tests/test_inworld_tts_service_factory.py

@@ -0,0 +1,54 @@
+from types import SimpleNamespace
+from unittest.mock import patch
+
+from api.services.configuration.registry import (
+    InworldTTSConfiguration,
+    ServiceProviders,
+)
+from api.services.pipecat.service_factory import create_tts_service
+
+
+def test_inworld_tts_configuration_defaults():
+    config = InworldTTSConfiguration(api_key="test-key")
+
+    assert config.provider == ServiceProviders.INWORLD
+    assert config.model == "inworld-tts-2"
+    assert config.voice == "Ashley"
+    assert config.language == "en-US"
+    assert config.delivery_mode == "BALANCED"
+
+
+def test_create_inworld_tts_service_uses_websocket_service_without_http_session():
+    user_config = SimpleNamespace(
+        tts=SimpleNamespace(
+            provider=ServiceProviders.INWORLD.value,
+            api_key="test-key",
+            model="inworld-tts-2",
+            voice="Ashley",
+            speed=1.1,
+            language="en-US",
+            delivery_mode="CREATIVE",
+        )
+    )
+    audio_config = SimpleNamespace(
+        transport_out_sample_rate=24000,
+        transport_in_sample_rate=16000,
+    )
+
+    with (
+        patch("api.services.pipecat.service_factory.aiohttp.ClientSession") as session,
+        patch("api.services.pipecat.service_factory.InworldTTSService") as mock_service,
+    ):
+        create_tts_service(user_config, audio_config)
+
+    session.assert_not_called()
+    assert mock_service.call_count == 1
+    kwargs = mock_service.call_args.kwargs
+    assert kwargs["api_key"] == "test-key"
+    assert "aiohttp_session" not in kwargs
+    assert "streaming" not in kwargs
+    assert kwargs["settings"].model == "inworld-tts-2"
+    assert kwargs["settings"].voice == "Ashley"
+    assert kwargs["settings"].language == "en-US"
+    assert kwargs["settings"].speaking_rate == 1.1
+    assert kwargs["settings"].delivery_mode == "CREATIVE"