fix: risk engine blocking sell orders on over-concentrated positions

Two bugs: (1) trading engine omitted estimated_value from sell order
jobs, causing risk engine to compute 0 reduction; (2) risk engine
applied position size limits to sells, trapping users in positions
they couldn't exit. Sells now always pass position value/pct checks.

services/trading/engine.py

@@ -728,6 +728,7 @@ class TradingEngine:
                                 "side": "sell",
                                 "quantity": sell_qty,
                                 "order_type": "market",
+                                "estimated_value": estimated_proceeds,
                                 "source": "trading_engine",
                             }
                             if self.redis is not None:
@@ -1813,14 +1814,17 @@ class TradingEngine:
                     self.portfolio_state.active_pool += current * qty
 
     async def _submit_sell_order(
-        self, ticker: str, quantity: int, reason: str
+        self, ticker: str, quantity: int, reason: str,
+        estimated_value: float = 0.0,
     ) -> None:
         """Push a sell order to the broker queue via Redis."""
         order_job = {
             "ticker": ticker,
             "action": "sell",
+            "side": "sell",
             "quantity": quantity,
             "order_type": "market",
+            "estimated_value": estimated_value,
             "source": "trading_engine",
             "reason": reason,
         }