Add streamlit app file

streamlit_app.py

@@ -0,0 +1,11 @@
+import sys
+from pathlib import Path
+
+# Ensure repo root is on sys.path for imports when running on Streamlit Cloud
+ROOT = Path(__file__).resolve().parent
+if str(ROOT) not in sys.path:
+    sys.path.insert(0, str(ROOT))
+
+from tradingagents.ui.dashboard import main
+
+main()