fix: tighten max-hold session countdown

app/services/paper_trade_service.py

@@ -441,22 +441,31 @@ async def list_trades(
     holding_sessions: dict[int, tuple[int, int]] = {}
     if policy["mode"] in ("time", "atr_trailing"):
         hold_days = int(policy["hold_days"])
-        for t, _ in rows:
-            if t.status != "open":
-                continue
-            held = int(
-                (
-                    await db.execute(
-                        select(func.count())
-                        .select_from(OHLCVRecord)
-                        .where(
-                            OHLCVRecord.ticker_id == t.ticker_id,
-                            OHLCVRecord.date > t.opened_at.date(),
-                        )
+        open_trades = [trade for trade, _ in rows if trade.status == "open"]
+        if open_trades:
+            ticker_ids = {trade.ticker_id for trade in open_trades}
+            earliest_opened = min(trade.opened_at.date() for trade in open_trades)
+            session_rows = (
+                await db.execute(
+                    select(OHLCVRecord.ticker_id, OHLCVRecord.date)
+                    .where(
+                        OHLCVRecord.ticker_id.in_(ticker_ids),
+                        OHLCVRecord.date > earliest_opened,
                     )
-                ).scalar_one()
-            )
-            holding_sessions[t.id] = (held, max(0, hold_days - held))
+                    .order_by(OHLCVRecord.ticker_id, OHLCVRecord.date)
+                )
+            ).all()
+            dates_by_ticker: dict[int, list[date]] = {}
+            for ticker_id, session_date in session_rows:
+                dates_by_ticker.setdefault(int(ticker_id), []).append(session_date)
+            for trade in open_trades:
+                dates = dates_by_ticker.get(trade.ticker_id, [])
+                held = len(dates) - bisect.bisect_right(
+                    dates, trade.opened_at.date()
+                )
+                # Do not clamp: a policy shortened below the current holding
+                # period must remain visible as overdue until the exit pass runs.
+                holding_sessions[trade.id] = (held, hold_days - held)
 
     trailing_info: dict[int, tuple[float, float | None]] = {}
     if policy["mode"] == "trailing":