fix: follow-up for salvaged PR #22263

- Restore allowed_chats gate before thread_id check so ignored_threads
  applies universally (even to guest mentions).
- Compute _message_mentions_bot once in _should_process_message to
  eliminate redundant second entity scan when guest_mode=true and the
  message does not mention the bot.
- Remove redundant _is_group_chat from _is_guest_mention (caller already
  verified the message is a group chat).
- Update _telegram_allowed_chats docstring to note guest_mode exception.
- Add test coverage: bot_command entity, text_mention entity,
  caption_entities, and ignored_threads + guest_mode interaction.
- Add nik1t7n to AUTHOR_MAP.

scripts/release.py

@@ -76,6 +76,7 @@ AUTHOR_MAP = {
     "ngusev@astralinux.ru": "NikolayGusev-astra",
     "liuguangyong201@hellobike.com": "liuguangyong93",
     "2093036+exiao@users.noreply.github.com": "exiao",
+    "20nik.nosov21@gmail.com": "nik1t7n",
     "thunderggnn@gmail.com": "ggnnggez",
     "haozhe4547@gmail.com": "ehz0ah",
     "kevyan1998@gmail.com": "kyan12",