Update app.py

app.py

@@ -484,7 +484,7 @@ def compute_gsd_metrics(diams: List[float], passing: List[float]) -> Dict[str, f
 # 4) Session state initialization
 if "sites" not in st.session_state:
     # initialize with a default site
-    st.session_state["sites"] = [{
+    st.session_state["sites"] = ({
         # ---------------------------
         # Basic Project Info
         # ---------------------------
@@ -581,7 +581,7 @@ if "sites" not in st.session_state:
         "report_convo_state": 0,
         "report_missing_fields": [],
         "report_answers": {}
-    }]
+    })
 
 
 if "active_site" not in st.session_state: