feat: implement AI model API proxy service

backend/app/routes/__init__.py

@@ -0,0 +1,8 @@
+"""API routes."""
+from fastapi import APIRouter
+from .health import router as health_router
+from .chat import router as chat_router
+from .openai import router as openai_router
+from .anthropic import router as anthropic_router
+
+__all__ = ["health_router", "chat_router", "openai_router", "anthropic_router"]