Debug tab: revert Data Inventory to plain button, no session_state or caption

visualization/debug_page.py

@@ -620,9 +620,7 @@ def render_debug(
     # ------------------------------------------------------------------
     st.subheader("Data Inventory")
 
-    show_library = st.toggle("Load Data Library", key="dbg_load_inventory")
-
-    if show_library:
+    if st.button("Load Data Library", key="dbg_load_inventory"):
         with st.expander("All database tables (row counts)", expanded=True):
             inv_df = _query_db_inventory(conn)
             if inv_df.empty:
@@ -652,8 +650,6 @@ def render_debug(
             st.dataframe(pd.DataFrame([overlap]), use_container_width=True, hide_index=True)
         elif overlap and "error" in overlap:
             st.warning(f"Overlap query error: {overlap['error']}")
-    else:
-        st.caption("Please allow a few moments to load the data library..")
 
     # --- Simulator raw rows ---
     with st.expander("Simulator raw rows", expanded=False):