Fix Bybit linear open orders query

tests/test_bybit_gateway.py

@@ -0,0 +1,28 @@
+from __future__ import annotations
+
+from typing import Any
+
+from llm_trade_bot.bybit_gateway import BybitGateway
+from llm_trade_bot.config import BybitConfig, ScannerConfig
+
+
+class FakeBybitHTTP:
+    def __init__(self) -> None:
+        self.open_order_requests: list[dict[str, Any]] = []
+
+    def get_open_orders(self, **parameters: Any) -> dict[str, Any]:
+        self.open_order_requests.append(parameters)
+        return {"retCode": 0, "result": {"list": []}}
+
+
+async def test_open_orders_scopes_linear_requests_by_settle_coin() -> None:
+    gateway = BybitGateway(BybitConfig("key", "secret", "USDC"), ScannerConfig())
+    http = FakeBybitHTTP()
+    gateway._http = http  # type: ignore[assignment]
+
+    await gateway.open_orders()
+
+    assert http.open_order_requests == [
+        {"category": "spot", "limit": 50},
+        {"category": "linear", "limit": 50, "settleCoin": "USDC"},
+    ]