Update src/app.py

src/app.py

@@ -112,13 +112,16 @@ with st.sidebar:
         user_api_key = st.text_input(
             "🔓 Unlock GPT-4o (Enter API Key)", 
             type="password", 
-            help="Enter your OpenAI API key to access GPT-4o. Press Enter to apply."
+            help="Enter your OpenAI API key to access GPT-4o. Press Enter to apply.",
+            key=f"user_key_{st.session_state.username}"
         )
         if user_api_key:
             st.session_state.user_openai_key = user_api_key
             st.caption("✅ Key Active")
         else:
             st.session_state.user_openai_key = None
+    else:
+        st.session_state.user_openai_key = None
 
     # 3. DYNAMICALLY ADD GPT-4o TO THE LIST
     # If Admin OR if they just entered a key, show the option