Update src/app.py

removed specific reference to k in the "if use_rag:" block to tie it directly to rag_engine.py versus having to change it every time in both scripts

src/app.py

@@ -293,8 +293,7 @@ with tab2:
                     # 1. Retrieve & Rerank (Now using the fixed function)
                     retrieved_docs = rag_engine.search_knowledge_base(
                         user_input, 
-                        st.session_state.username, 
-                        k=3
+                        st.session_state.username
                     )
                     
                     if retrieved_docs: