Change initial sidebar state to collapsed for improved user experience

app.py

@@ -111,7 +111,7 @@ def main():
     st.set_page_config(
         page_title="Divrey Yoel AI Chat (GPT-4o Gen)", 
         layout="wide", 
-        initial_sidebar_state="expanded"
+        initial_sidebar_state="collapsed"
     )
 
     # Initialize session state variables if not already set