[2026-05-18] 포지션 DB 동기화 + pnl 계산 수정

- order_executor: _update_trade_exit에 pnl 계산 저장 추가
- main: 매수 시 positions DB INSERT, 매도 시 DELETE
- main: 재시작 시 DB에서 positions 복원 (_restore_positions_from_db)

app/execution/order_executor.py

@@ -88,15 +88,21 @@ class OrderExecutor:
     def _update_trade_exit(self, ticker, exit_price,
                             qty, reason, fee):
         with get_conn() as conn:
+            row = conn.execute("""
+                SELECT id, entry_price, quantity FROM trades
+                WHERE ticker=? AND exit_time IS NULL
+                ORDER BY id DESC LIMIT 1
+            """, (ticker,)).fetchone()
+            if not row:
+                return
+            trade_id, entry_price, trade_qty = row
+            actual_qty = qty if qty else trade_qty
+            pnl = (exit_price - entry_price) * actual_qty - fee
             conn.execute("""
                 UPDATE trades
-                SET exit_time=?, exit_price=?, exit_reason=?, fee=fee+?
-                WHERE id = (
-                    SELECT id FROM trades
-                    WHERE ticker=? AND exit_time IS NULL
-                    ORDER BY id DESC LIMIT 1
-                )
+                SET exit_time=?, exit_price=?, exit_reason=?, fee=fee+?, pnl=?
+                WHERE id=?
             """, (
                 datetime.now().strftime("%H:%M:%S"),
-                exit_price, reason, fee, ticker,
+                exit_price, reason, fee, pnl, trade_id,
             ))