Update app.py

app.py

@@ -243,6 +243,17 @@ if research_button and topic:
     except Exception as e:
         st.error(f"❌ Error: {e}")
 
+
+# 🧠 Initialize session state
+if "last_report" not in st.session_state:
+    st.session_state["last_report"] = ""
+if "follow_up_input" not in st.session_state:
+    st.session_state["follow_up_input"] = ""
+if "methodology_notes" not in st.session_state:
+    st.session_state["methodology_notes"] = ""
+if "chat_history" not in st.session_state:
+    st.session_state["chat_history"] = []
+
 # --- Methodology Recommender ---
 st.divider()
 st.subheader("🧪 Methodology Recommender")