chore: finalize broker qty metadata consistency

Co-authored-by: genichin <4282227+genichin@users.noreply.github.com>

trex_core/application/account_snapshot.py

@@ -222,12 +222,15 @@ class AccountSnapshotService:
 
         Unlike ``holdings_for_sell()``, this read path never performs a live broker
         call and therefore cannot mutate broker state or mask snapshot staleness.
+        Freshness uses the same ``sell_max_age_sec`` policy (`self._sell_max_age`)
+        as pending-sell quantity protection so strategy reads and sell dispatch
+        share one stale-snapshot threshold.
         """
         snapshot = self._load_current()
-        self._age(snapshot.holdings_captured_at, self._sell_max_age)
         captured_at = snapshot.holdings_captured_at
         if captured_at is None:
             raise AccountSnapshotUnavailable("not_ready")
+        self._age(captured_at, self._sell_max_age)
         return list(snapshot.holdings), captured_at
 
     def buy_guard(