feat: implement chatbot engine for project validation, classification, and session management

src/recommendation_engine/chatbot_engine.py

@@ -532,7 +532,7 @@ def chatbot(user_id: str, user_input: str):
             else:
                 state["domain"] = domain
                 state["waiting_for_domain"] = False
-        elif user_input.lower().strip() == "idea":
+        elif not any(w in user_input.lower() for w in FOLLOWUP_WORDS):
             state["domain"] = None
             
         if not state.get("domain"):