Add Binance SIM market adapter and exchange switch in settings.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/main.py

@@ -89,6 +89,13 @@ async def health() -> dict:
     from .strategy.session import get_session
 
     settings = get_settings()
+    try:
+        from .exchange.runtime import load_runtime_settings
+
+        rt = load_runtime_settings()
+        exchange_name = rt.exchange
+    except Exception:
+        exchange_name = settings.exchange
     sess = get_session()
     snap = sess.snapshot()
     try:
@@ -99,7 +106,7 @@ async def health() -> dict:
         "ok": True,
         "mode": settings.mode,
         "env_name": settings.env_name,
-        "exchange": settings.exchange,
+        "exchange": exchange_name,
         "sim": settings.is_sim,
         "market_connected": snap.connected,
         "pair": snap.pair.to_dict() if snap.pair else None,