feat(deribit): get_open_orders (limit resting + trigger non scattati)

Espone private/get_open_orders_by_currency sul router Deribit (pattern gia'
presente per Hyperliquid/IBKR). Serve al reconciler resting di PythagorasGoal:
TP/DSL attesi dai libri vs ordini realmente in book (caso MR02_BTC 2026-06-12:
TP resting fillato di notte + disaster-SL sparito, scoperti solo al close sim).
NB: per i trigger untriggered interrogare anche type='trigger_all' e fare
merge per order_id.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/cerbero_mcp/exchanges/deribit/client.py

@@ -412,6 +412,37 @@ class DeribitClient:
             "testnet": self.testnet,
         }
 
+    async def get_open_orders(
+        self, currency: str = "USDC", kind: str | None = None, type: str = "all"
+    ) -> list:
+        """Ordini APERTI sul conto: limit resting e trigger non scattati.
+        NB Deribit: con type='all' gli untriggered possono essere omessi ->
+        chi vuole anche i bracket interroga type='trigger_all' e merge per
+        order_id (e' cio' che fa il reconciler di PythagorasGoal)."""
+        params: dict = {"currency": currency, "type": type}
+        if kind:
+            params["kind"] = kind
+        raw = await self._request("private/get_open_orders_by_currency", params)
+        result = raw.get("result") or []
+        return [
+            {
+                "order_id": o.get("order_id"),
+                "instrument": o.get("instrument_name"),
+                "direction": o.get("direction"),
+                "order_type": o.get("order_type"),
+                "order_state": o.get("order_state"),
+                "amount": o.get("amount"),
+                "filled_amount": o.get("filled_amount"),
+                "price": o.get("price"),
+                "trigger_price": o.get("trigger_price"),
+                "reduce_only": o.get("reduce_only"),
+                "label": o.get("label"),
+                "creation_timestamp": o.get("creation_timestamp"),
+            }
+            for o in result
+            if isinstance(o, dict)
+        ]
+
     async def get_trade_history(
         self, limit: int = 100, instrument_name: str | None = None
     ) -> list: