feat: implement AI model API proxy service

backend/app/routes/health.py

@@ -0,0 +1,10 @@
+"""Health check endpoint."""
+from fastapi import APIRouter
+
+router = APIRouter(tags=["health"])
+
+
+@router.get("/health")
+async def health_check():
+    """Health check endpoint."""
+    return {"status": "ok"}