feat: implement api/config endpoint

src/server/config_request.py

@@ -0,0 +1,13 @@
+# Copyright (c) 2025 Bytedance Ltd. and/or its affiliates
+# SPDX-License-Identifier: MIT
+
+from pydantic import BaseModel, Field
+
+from src.server.rag_request import RAGConfigResponse
+
+
+class ConfigResponse(BaseModel):
+    """Response model for server config."""
+
+    rag_config: RAGConfigResponse = Field(..., description="The config of the RAG")
+    configured_llms: dict[str, list[str]] = Field(..., description="The configured LLM")