fix changing models bug

there bug in utils function which is when set model name to gemini or any other model name it don't effect this functions and remain gpt-4o-mini to solve this i will set variable name to model name model=os.environ.get("llm_model") or model in each function

Author: mohamed-em2m

memoryos-pypi/memoryos.py

@@ -44,6 +44,7 @@ def __init__(self, user_id: str,
         self.assistant_id = assistant_id
         self.data_storage_path = os.path.abspath(data_storage_path)
         self.llm_model = llm_model
+        os.environ["llm_model"]= llm_model
         self.mid_term_similarity_threshold = mid_term_similarity_threshold
 
         print(f"Initializing Memoryos for user '{self.user_id}' and assistant '{self.assistant_id}'. Data path: {self.data_storage_path}")
@@ -328,4 +329,4 @@ def force_mid_term_analysis(self):
         self.mid_term_heat_threshold = original_threshold # Restore original threshold
 
     def __repr__(self):
-        return f"<Memoryos user_id='{self.user_id}' assistant_id='{self.assistant_id}' data_path='{self.data_storage_path}'>" 
+        return f"<Memoryos user_id='{self.user_id}' assistant_id='{self.assistant_id}' data_path='{self.data_storage_path}'>"