Update src/streamlit_app.py

src/streamlit_app.py

@@ -108,7 +108,7 @@ h1, h2, h3 {color: #f3f4f6; font-weight: 600;}
 """, unsafe_allow_html=True)
 
 # ==========================================================
-# 🧭 SIDEBAR — SIMPLE
+# 🧭 SIDEBAR — STABLE, NO RERUN
 # ==========================================================
 with st.sidebar:
     st.markdown("### 🧭 Response Mode")
@@ -120,8 +120,23 @@ with st.sidebar:
     )
 
     st.markdown("---")
-    show_advanced = st.checkbox("Show advanced settings (for developers)", value=False)
-    if show_advanced:
+
+    # 🧠 Advanced settings — persistent, no rerun
+    if "show_advanced" not in st.session_state:
+        st.session_state.show_advanced = False
+
+    show_advanced_now = st.checkbox(
+        "Show advanced settings (for developers)",
+        value=st.session_state.show_advanced,
+        key="show_adv_checkbox"
+    )
+
+    # Detect toggle change without triggering full rerun
+    if show_advanced_now != st.session_state.show_advanced:
+        st.session_state.show_advanced = show_advanced_now
+        st.stop()  # ✅ Prevents full rerun — keeps doc & state intact
+
+    if st.session_state.show_advanced:
         st.markdown("### Developer Settings")
         chunk_size = st.slider("Chunk Size (characters)", 200, 1500, 1000, step=50)
         overlap = st.slider("Chunk Overlap (characters)", 50, 200, 120, step=10)
@@ -133,7 +148,7 @@ with st.sidebar:
     st.caption("✨ Built by Shubham Sharma")
 
 # ==========================================================
-# 🧠 SESSION STATE
+# 🧠 SESSION STATE INITIALIZATION
 # ==========================================================
 for key, val in {
     "user_query_input": "",