fix(telegram): cancel delayed deliveries on disconnect

[CRWuTJ]

Summary

• cancel pending Telegram delayed delivery task families during disconnect
• clear text/photo/media batch queues and polling error task state after cancellation
• add regression coverage for stale text batches and all pending delivery maps

Tests

• python -m pytest tests/gateway/test_telegram_text_batching.py -q
• python -m pytest tests/gateway/test_telegram_text_batching.py tests/gateway/test_telegram_network_reconnect.py tests/gateway/test_telegram_conflict.py -q

[teknium1]

Merged via #55971. Your fix was salvaged onto current main (the Telegram adapter moved to plugins/platforms/telegram/adapter.py since you opened this) with your authorship preserved in git log. Thanks for catching the disconnect-race delivery bug!