feat(telegram): sync auto-generated session titles to forum topic names

[cola-runner]

Summary

Closes #16255. Connects two systems that were developed independently:

• agent/title_generator.py generates a session title and saves it to SQLite.
• gateway/platforms/telegram.py creates / tracks forum topics but never updates their names after creation.

After this PR, when a session title is auto-generated or set manually via /title, the corresponding Telegram forum topic name is updated via editForumTopic so the topic list and /history stay in sync.

Architecture

Three small layers, no behaviour change for non-Telegram platforms:

1. BasePlatformAdapter.update_topic_title — new async hook, default no-op. Platforms with per-thread titles override it. Errors must be swallowed by the implementation — title sync is best-effort UX.
2. TelegramAdapter.update_topic_title — calls editForumTopic with the new name, truncates to Telegram's 128-char limit, skips the implicit "General" topic (its name is owned by the chat, not the bot), DEBUG-logs Bot API failures, and re-aligns the local _dm_topics cache so /resume lookups by name still find the renamed topic.
3. title_generator — adds an on_title_set callback that fires after the new title is persisted to SQLite. Callback exceptions are swallowed so a flaky platform call can't crash the daemon worker.

Sync→async bridge

maybe_auto_title runs in a daemon threading.Thread, so we hop back to the gateway loop via asyncio.run_coroutine_threadsafe:

• GatewayRunner._make_topic_title_sync_callback builds the callback (skipping early when the source has no thread_id — most non-forum chats).
• GatewayRunner._sync_topic_title_to_platform looks up the right adapter and awaits its update_topic_title.

The /title command reuses the same _sync_topic_title_to_platform so manual renames push to the platform immediately.

Files

• gateway/platforms/base.py — new update_topic_title no-op default
• gateway/platforms/telegram.py — Telegram override + cache realignment
• agent/title_generator.py — on_title_set callback through maybe_auto_title / auto_title_session
• gateway/run.py — gateway helpers + wires both auto-title and /title
• tests/agent/test_title_generator.py — 5 new tests for the callback
• tests/gateway/test_telegram_topic_title.py — 13 new tests for the override

Test plan

• pytest tests/agent/test_title_generator.py tests/gateway/test_telegram_topic_title.py tests/gateway/test_telegram_format.py — 125 passed locally
• No-op for non-Telegram adapters (covered by base test)
• Cache stays consistent across renames (covered)
• Bot API errors don't propagate (covered)
• Truncation to 128-char Telegram limit (covered)

[alt-glitch]

Likely duplicate of #9921 — same feature: auto-rename Telegram forum topics on session title change. Both close #16255.

[teknium1]

Thanks for the Telegram topic-title synchronization work. The member duplicate note linking #9921 was correct: current main now provides the requested behavior through a more guarded, current gateway implementation.

Automated hermes-sweeper review evidence:

• agent/title_generator.py:154 persists an auto-generated title before invoking title_callback; gateway/run.py:19015 wires that callback for Telegram topic lanes.
• gateway/run.py:13612 performs the guarded best-effort rename, including topic/session binding validation, operator-topic preservation, and disable_topic_auto_rename support; gateway/run.py:13720 schedules it safely from the title worker.
• gateway/slash_commands.py:3487 sends successful manual /title updates through the same scheduler. This shipped in 38f1a923af6e77cad16a4a270c74f79847311c2b (v2026.7.1).
• Regression coverage is present in tests/gateway/test_telegram_topic_mode.py:889 and tests/gateway/test_title_command.py:173.