Enhance workflow routing and agent configuration management

- Introduce WorkflowLLMRouter for pre-response LLM routing, allowing agents to determine the appropriate function to call based on user input.
- Implement UserTurnRoutingProcessor to manage user turns before reaching the LLM, ensuring proper routing and handling of user messages.
- Refactor WorkflowBrain to integrate new routing logic and enhance agent stage configuration, including entry modes and resource management.
- Update service factory to support dynamic LLM resource configuration based on workflow settings.
- Add tests for new routing functionality and ensure proper handling of user messages in various scenarios.

backend/services/pipecat/service_factory.py

@@ -29,11 +29,18 @@ TTS_STOP_FRAME_TIMEOUT_S = 1.0
 def config_with_resource(
     cfg: AssistantConfig, resource: RuntimeModelResource
 ) -> AssistantConfig:
-    """Return a call-local config view for one workflow ASR/TTS resource."""
+    """Return a call-local config view for one workflow model resource."""
     result = cfg.model_copy(deep=True)
     values = resource.values or {}
     secrets = resource.secrets or {}
-    if resource.capability == "ASR":
+    if resource.capability == "LLM":
+        result.model = str(values.get("modelId") or "")
+        result.llm_interface_type = resource.interface_type
+        result.llm_values = values
+        result.llm_secrets = secrets
+        result.llm_api_key = str(secrets.get("apiKey") or "")
+        result.llm_base_url = str(values.get("apiUrl") or "")
+    elif resource.capability == "ASR":
         result.asr = str(values.get("modelId") or "")
         result.stt_language = str(values.get("language") or "")
         result.stt_interface_type = resource.interface_type
@@ -51,7 +58,7 @@ def config_with_resource(
         result.tts_api_key = str(secrets.get("apiKey") or "")
         result.tts_base_url = str(values.get("apiUrl") or "")
     else:
-        raise ValueError(f"工作流语音资源能力无效:{resource.capability}")
+        raise ValueError(f"工作流模型资源能力无效:{resource.capability}")
     return result