fix: inactive user cleanup deletes users with paid subscriptions

The get_inactive_users query filtered only by last_activity (last bot
interaction), ignoring subscription end dates. Users who bought long
subscriptions (3-6-12 months) but didn't interact with the bot got
flagged as inactive and deleted+banned while their subscription was
still active or recently expired.

Fix: add SQL subquery excluding users who have ANY subscription with
end_date >= threshold_date. A user is now only deletable when BOTH
their last_activity AND their latest subscription end_date are older
than the configured inactivity period.

app/database/crud/user.py

@@ -1112,6 +1112,12 @@ async def get_users_for_promo_segment(db: AsyncSession, segment: str) -> list[Us
 async def get_inactive_users(db: AsyncSession, months: int = 3) -> list[User]:
     threshold_date = datetime.now(UTC) - timedelta(days=months * 30)
 
+    # Подзапрос: пользователи, у которых есть подписка с end_date >= threshold
+    # (активная или недавно истёкшая) — таких удалять нельзя
+    users_with_recent_subs = (
+        select(Subscription.user_id).where(Subscription.end_date >= threshold_date).distinct().scalar_subquery()
+    )
+
     result = await db.execute(
         select(User)
         .options(
@@ -1120,7 +1126,13 @@ async def get_inactive_users(db: AsyncSession, months: int = 3) -> list[User]:
             selectinload(User.referrer),
             selectinload(User.promo_group),
         )
-        .where(and_(User.last_activity < threshold_date, User.status == UserStatus.ACTIVE.value))
+        .where(
+            and_(
+                User.last_activity < threshold_date,
+                User.status == UserStatus.ACTIVE.value,
+                User.id.not_in(users_with_recent_subs),
+            )
+        )
     )
     users = result.scalars().all()