Add OKX-style funds bar with USDT/USDC convert and transfer.

SIM uses multi-wallet balances; LIVE hits OKX asset/account APIs and spot USDC-USDT swap. Funds strip hides sim labeling.

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

backend/app/strategy/engine.py

@@ -126,6 +126,7 @@ class StrategyEngine:
             "ledger": self.ledger.snapshot(),
             "mode": "SIM" if s.is_sim else "LIVE",
             "sim": s.is_sim,
+            "exchange": str(s.exchange or "okx").lower(),
             "live_ready": (live_ready()[0] if not s.is_sim else True),
             "live_ready_reason": (live_ready()[1] if not s.is_sim else "sim"),
             "show_manual_trade_buttons": self.ledger.get_setting_bool(