Add Volcengine support for TTS and ASR services

- Introduced Volcengine as a new provider for both TTS and ASR services.
- Updated configuration files to include Volcengine-specific parameters such as app_id, resource_id, and uid.
- Enhanced the ASR service to support streaming mode with Volcengine's API.
- Modified existing tests to validate the integration of Volcengine services.
- Updated documentation to reflect the addition of Volcengine as a supported provider for TTS and ASR.
- Refactored service factory to accommodate Volcengine alongside existing providers.

engine/tests/test_asr_factory_modes.py

@@ -1,6 +1,7 @@
 from providers.asr.buffered import BufferedASRService
 from providers.asr.dashscope import DashScopeRealtimeASRService
 from providers.asr.openai_compatible import OpenAICompatibleASRService
+from providers.asr.volcengine import VolcengineRealtimeASRService
 from providers.factory.default import DefaultRealtimeServiceFactory
 from runtime.ports import ASRServiceSpec
 
@@ -35,6 +36,29 @@ def test_create_asr_service_openai_compatible_returns_offline_provider():
     assert service.enable_interim is False
 
 
+def test_create_asr_service_volcengine_returns_streaming_provider():
+    factory = DefaultRealtimeServiceFactory()
+    service = factory.create_asr_service(
+        ASRServiceSpec(
+            provider="volcengine",
+            mode="streaming",
+            sample_rate=16000,
+            api_key="test-key",
+            api_url="wss://openspeech.bytedance.com/api/v3/sauc/bigmodel",
+            model="bigmodel",
+            app_id="app-1",
+            uid="caller-1",
+            request_params={"end_window_size": 800},
+        )
+    )
+    assert isinstance(service, VolcengineRealtimeASRService)
+    assert service.mode == "streaming"
+    assert service.protocol == "seed"
+    assert service.app_id == "app-1"
+    assert service.uid == "caller-1"
+    assert service.request_params["end_window_size"] == 800
+
+
 def test_create_asr_service_fallback_buffered_for_unsupported_provider():
     factory = DefaultRealtimeServiceFactory()
     service = factory.create_asr_service(