set provider nebius by default

agent.py

@@ -49,7 +49,7 @@ class QAgent:
         
         if model_type == "InferenceClientModel":
             if api_key is None:
-                api_key = os.getenv("SP_HF_TOK")
+                api_key = os.getenv("Q_NEB_TOK")
                 if not api_key:
                     raise ValueError("No API Key found for HuggingFace. Please set SP_HF_TOK or pass api_key.")
             
@@ -58,7 +58,7 @@ class QAgent:
                 
             self.model = InferenceClientModel(
                 model_id=model_id or "Qwen/Qwen2.5-Coder-32B-Instruct", # précédemment : or "meta-llama/Llama-3-70B-Instruct",
-                provider=provider or "hf-inference",
+                provider=provider or "nebius" # or "hf-inference",
                 token=api_key,
                 timeout=timeout or 120
                 # temperature=temperature