fixed ddl key issue

src/chat_ui.py

@@ -166,7 +166,7 @@ def render_chat():
 
                 # Add download button for results
                 csv = df.to_csv(index=False).encode("utf-8")
-                st.download_button("📥 Download CSV", csv, "results.csv", "text/csv")
+                st.download_button("📥 Download CSV", csv, "results.csv", "text/csv", key=f"download_csv_{id(msg)}")
 
             if msg.get("chart"):
                 img_data = base64.b64decode(msg["chart"])
@@ -235,7 +235,7 @@ def render_chat():
 
                     # Add download button for results
                     csv = df.to_csv(index=False).encode("utf-8")
-                    st.download_button("\U0001F4C5 Download CSV", csv, "results.csv", "text/csv")
+                    st.download_button("\U0001F4C5 Download CSV", csv, "results.csv", "text/csv", key=f"download_csv_{id(msg)}")
 
                 if msg.get("chart"):
                     img_data = base64.b64decode(msg["chart"])