Summary

Adds native support for per-topic skill binding and automatic topic discovery in Telegram group forum (supergroup) chats. Closes #4622, Closes #3716

What Changed

gateway/platforms/telegram.py (+66 lines):

Skill Binding

1. Config Loading (__init__) — Reads group_topics from platforms.telegram.extra config
2. _get_group_topic_info() — Looks up topic config by chat_id + thread_id
3. _reload_group_topics_from_config() — Hot-reloads group_topics from config.yaml without restart
4. _build_message_event() branch — Resolves group topic skill binding and passes as auto_skill

Auto-Discovery (Lifecycle Events)

5. _persist_group_topic() — Auto-registers new topics to config.yaml
6. _persist_group_topic_edit() — Handles renames and close/reopen state
7. _build_message_event() lifecycle handlers:
   • forum_topic_created — auto-persist new topic with name + thread_id + icon
   • forum_topic_edited — update topic name in config
   • forum_topic_closed — mark topic as closed
   • forum_topic_reopened — mark topic as reopened

gateway/run.py (+1/-1):

• Fix metadata source: use message instead of event for first-response send

Key Features

• Single bot, multiple roles per group
• Auto-discovery — new topics register automatically, no manual config
• Full lifecycle — create, rename, close, reopen all tracked
• Hot-reloadable — add topics to config.yaml without restart
• Zero breaking changes — fully backward compatible
• Mirrors existing dm_topics pattern for consistency

Testing

• Messages in configured topic trigger correct skill loading
• Messages in unconfigured topics use default behavior
• Hot-reload works without gateway restart
• Multiple groups with different configs work independently
• New topic creation auto-registers to config.yaml
• Topic rename updates config.yaml
• Topic close/reopen tracked in config
• Backward compatible: no config = no change