fix(tg): QA fixes — stream_message, topic_created, archive reply

- sdk/mock.py: stream_message was async def (coroutine), must be async
  generator with yield — caused TypeError on every user message
- topic_events.py: on_topic_created now skips bot-created topics
  (from_user.id == bot.id); cmd_new already registers them under the
  correct human user_id
- commands.py: cmd_archive now sends "Чат архивирован." confirmation
- test_topic_events.py: add bot=SimpleNamespace(id=BOT_ID) to fixture

adapter/telegram/handlers/commands.py

@@ -54,6 +54,7 @@ async def cmd_archive(message: Message) -> None:
     except TelegramBadRequest as e:
         logger.warning("cmd_archive_bot_error", error=str(e))
     db.archive_chat(user_id=user_id, thread_id=thread_id)
+    await message.answer("Чат архивирован.")
     logger.info("cmd_archive", user_id=user_id, thread_id=thread_id)