fix: call set_page_config before heavy imports; patch duplicate call

streamlit_app.py

@@ -1,21 +1,32 @@
 import sys, os, traceback
 from pathlib import Path
+import streamlit as st
 
-# Make env.*, reward.*, agents.* (from repo root) and orchestrator_widget
-# (from demo/) importable before demo/streamlit_app.py starts.
+# ── 1. Page config fires immediately so the browser gets a live response
+#       before the 10-30 s ML imports below.
+st.set_page_config(
+    page_title="SpindleFlow RL",
+    page_icon="⚡",
+    layout="wide",
+    initial_sidebar_state="collapsed",
+)
+
+# ── 2. Silence the duplicate set_page_config call inside demo/streamlit_app.py
+#       (it also has one at module level — would raise StreamlitAPIException).
+_real_spc = st.set_page_config
+st.set_page_config = lambda *a, **kw: None
+
+# ── 3. Make env.*, reward.*, agents.* and orchestrator_widget importable.
 _root = Path(__file__).resolve().parent
 for _p in (str(_root), str(_root / "demo")):
     if _p not in sys.path:
         sys.path.insert(0, _p)
 os.chdir(str(_root))
 
-import streamlit as st   # needed only for the error fallback below
-
+# ── 4. Run demo/streamlit_app.py exactly as __main__.
+#       Its st.set_page_config() call is now a no-op; main() draws the UI.
 _demo = _root / "demo" / "streamlit_app.py"
 try:
-    # Run demo/streamlit_app.py exactly as if it were the entry-point script.
-    # __file__ must point to the demo file so its own Path(__file__) logic
-    # resolves paths correctly (e.g. demo/assets, orchestrator_widget).
     exec(
         compile(_demo.read_text(encoding="utf-8"), str(_demo), "exec"),
         {"__file__": str(_demo), "__name__": "__main__"},
@@ -25,3 +36,5 @@ except SystemExit:
 except Exception as exc:
     st.error(f"SpindleFlow failed to load: {exc}")
     st.code(traceback.format_exc())
+finally:
+    st.set_page_config = _real_spc   # restore for subsequent Streamlit re-runs