Add openai to pyproject.toml

pyproject.toml

@@ -14,7 +14,7 @@ dependencies = [
     "pydantic>=2.0.0",
     "uvicorn>=0.24.0",
     "requests>=2.31.0",
-    # No additional dependencies — pure Python implementation
+    "openai>=1.0.0"
 ]
 
 [project.optional-dependencies]