Adds a new section 'Multi-session DM mode (/topic)' to the Telegram
messaging docs, covering:
- Comparison table vs the existing config-driven extra.dm_topics
- BotFather prerequisites (Threads Settings, user-create permission)
- Activation flow and root-DM lobby behavior
- End-user flow for creating topics via the + button / All Messages
- Auto-renaming when Hermes generates session titles
- /new semantics inside a topic
- /topic <session-id> restore of previous sessions
- Persistence layout (SQLite side tables)
- How to disable the feature
Also:
- New /topic row in the messaging slash-commands reference
- Updated Bot API 9.4 summary to point at both topic features
1a9542cf75