suppress periodic notifications for stale collapsed backlogs

The backlog-collapse fix (previous commit) correctly stops the checkpoint
from falling further behind, but it was still sending the full per-game
notification for whatever it caught up on — meaning a gamer whose checkpoint
had drifted weeks behind now dumps a multi-week, game-by-game report on the
user in one message. That's not a "periodic update" anymore, just spam.

When the collapsed window exceeds 2 hours, catch the checkpoint up silently
(still fixes the drift) but skip sending the notification for it — only
report activity that's actually recent going forward.

LichessClientTG_bot/bot.py

@@ -1626,6 +1626,19 @@ class LichessBot:
                     since_time = period_end_approx - timedelta(minutes=period_minutes)
                     logger.info(f"📌 First check: period from {since_time} to {period_end_approx}")
 
+                # A collapsed backlog spanning way more than a normal check window isn't
+                # "recent activity" anymore — dumping a multi-week, game-by-game report
+                # on the user reads as spam, not a periodic update. Catch the checkpoint
+                # up silently in that case instead of sending the full notification.
+                STALE_BACKLOG_THRESHOLD = timedelta(hours=2)
+                is_stale_backlog = (period_end_approx - since_time) > STALE_BACKLOG_THRESHOLD
+                if is_stale_backlog:
+                    logger.warning(
+                        f"⏭️ {username}: collapsed window ({since_time} to {period_end_approx}) "
+                        f"exceeds {STALE_BACKLOG_THRESHOLD}; catching up checkpoint silently, "
+                        f"no notification will be sent for this stale backlog"
+                    )
+
                 since_timestamp = int(since_time.timestamp() * 1000)
                 # Используем приблизительное время как until_timestamp
                 # После получения ответа пересчитаем фактическое время
@@ -1737,12 +1750,13 @@ class LichessBot:
                 
                 logger.info(f"🔍 Activity check result for {username}: has_games={has_games} (total={total_games}), has_puzzles={has_puzzles} (total={total_puzzles})")
                 
-                # Отправляем уведомление только если есть реальная активность.
+                # Отправляем уведомление только если есть реальная активность и это не
+                # молчаливый догон устаревшего бэклога (is_stale_backlog, см. выше).
                 # Ошибки форматирования/отправки НЕ перехватываются здесь: они должны
                 # всплыть во внешний обработчик, чтобы чекпоинт не продвинулся и уже
                 # обнаруженная активность была отправлена повторно на следующей попытке,
                 # а не потеряна молча.
-                if has_games or has_puzzles:
+                if (has_games or has_puzzles) and not is_stale_backlog:
                     logger.info(f"📊 Activity detected for {gamer['username']}, preparing notification...")
                     user_lang = self.db.get_user_language(user_id)
                     # Label the notification with the actual queried window, not the
@@ -1765,6 +1779,8 @@ class LichessBot:
                     logger.info(f"✅ Sent periodic notification for {gamer['username']} to user {user_id}")
                     # Increment periodic notification counter
                     self.counters.increment('periodic_notification')
+                elif is_stale_backlog and (has_games or has_puzzles):
+                    logger.info(f"⏭️ Suppressed stale backlog notification for {gamer['username']} (had activity, but window too old)")
                 else:
                     logger.debug(f"⏭️ No activity found for {gamer['username']} in the last {period_minutes} minutes")