Fix production bug on num chapter

pages/chapter_params.py

@@ -23,7 +23,7 @@ def page():
     tabs = st.tabs([part['title'] for part in parts_sorted])
     for part, tab in zip(parts_sorted, tabs):
         with tab:
-            k = f"area_{part["num"]}"
+            k = f"area_{part['num']}"
             st.text_area(
                 "Prompt System",
                 part['prompt_system'],