Problem

Since b323957 ("fix(telegram): preserve DM topic routing via reply fallback"), the telegram.reply_to_mode = "off" user setting has been silently ignored whenever the user has DM topics configured (platforms.telegram.extra.dm_topics). Every bot reply gets a quote bubble of the user's message attached, even though the user explicitly opted out.

The DM-topic-fallback path in send(), _reply_to_message_id_for_send, and _thread_kwargs_for_send unconditionally injects reply_to_message_id so the message visually lands in the right private-chat "topic" (Telegram DMs don't have native forum topics — Hermes fakes them via reply chains). That override breaks the user preference.

Reproduction:

# ~/.hermes/config.yaml
telegram:
  reply_to_mode: "off"
platforms:
  telegram:
    extra:
      dm_topics:
        - chat_id: <your-id>
          topics:
            - name: Daily chat
              thread_id: <thread-id>

→ Every bot reply still attaches a quote bubble of the user's message.

Fix

When reply_to_mode == "off", skip the reply anchor and rely on message_thread_id alone for DM-topic routing. Verified live on python-telegram-bot's reference client — messages still land in the correct private topic, quote bubble gone.

Two private helpers (_reply_to_message_id_for_send, _thread_kwargs_for_send) become instance methods (were @classmethod) so they can read self._reply_to_mode. All call sites already use self.xxx(...) — no caller changes needed.

Trade-off

b323957's commit message notes "either parameter alone can render outside the visible lane" on some clients. In practice on python-telegram-bot's reference client message_thread_id alone is sufficient. If a client genuinely needs the reply anchor for routing, users can keep reply_to_mode = "first" (the default) — only users who explicitly opt out are affected by this change.

Tests

New TestDmTopicReplyFallback class in tests/gateway/test_telegram_reply_mode.py:

• mode=off drops the implicit DM-topic reply anchor
• mode=first / mode=all keep it (existing behavior preserved)
• mode=off honours an explicitly provided reply_to (media reply path)
• thread kwargs emit message_thread_id alone under mode=off
• end-to-end send() verifies no quote bubble, topic still routed
• regression guard for the b323957 DM-topic-anchor behavior

$ pytest tests/gateway/test_telegram_reply_mode.py tests/gateway/test_telegram_thread_fallback.py
72 passed in 5.08s

Also verified live in production DM topic for ~30 minutes — quote bubbles gone, no message lost to wrong topic.