Summary

Salvage of #22053 by @leehack onto current main, fixing #22022 (Telegram Bot API 10.0 broke private-chat topic replies — Hermes responses landed in "All Messages" instead of the active DM topic lane).

Root cause (from #22022)

Bot API 10.0 changed how Telegram routes outbound sends in private-chat topic lanes. Previously, sendMessage(message_thread_id=N) worked. After 10.0, the same call fails with Bad Request: message thread not found. Hermes' existing fallback retried without the thread id, dropping the response into the root chat.

Fix (from #22053, by @leehack)

Three distinct routing modes:

1. Forum / supergroup topics — keep using message_thread_id (unchanged).
2. True Bot API Direct Messages topics — explicit direct_messages_topic_id metadata opt-in.
3. Hermes-created private DM topic lanes — reply-anchor fallback (send message_thread_id together with a reply_to_message_id pointing at the triggering user message; if either is missing, drop both rather than land in the wrong lane).

Threaded through new _thread_metadata_for_source(source, reply_to_message_id) and _reply_anchor_for_event(event) helpers in gateway/platforms/base.py, then wired into ~15 outgoing send sites in gateway/run.py and all media/keyboard sends in gateway/platforms/telegram.py.

Follow-up fix (added during salvage review)

send_typing was the one outgoing site #22053 didn't update because Telegram's send_chat_action only accepts message_thread_id (no direct_messages_topic_id equivalent). Without a fix, every typing tick (~every 2s during agent runs) makes a doomed API call that gets logged at debug level. This salvage adds a short-circuit: when metadata indicates a DM topic reply-fallback lane, skip the call entirely. User-visible behavior is unchanged (no typing indicator either way for these lanes), but logs stay clean.

Verification

bash scripts/run_tests.sh \
  tests/gateway/test_telegram_thread_fallback.py \
  tests/gateway/test_run_progress_topics.py \
  tests/gateway/test_background_command.py \
  tests/gateway/test_voice_command.py \
  tests/gateway/test_discord_free_response.py \
  tests/gateway/test_feishu.py
=> 480 passed

Lint diff (scripts/lint_diff.py): 🆕 New issues: none for both ruff and ty.

Closes / supersedes

• Fixes Telegram Bot API 10 breaks private chat topic replies; Hermes falls back to All Messages #22022 — Telegram Bot API 10.0 breaks private-chat topic replies
• Fixes [Bug]: send_model_picker bypasses _message_thread_id_for_send — "Message thread not found" in topic groups #12839 — send_model_picker bypasses _message_thread_id_for_send (incidentally fixed; model picker now goes through the new _thread_kwargs_for_send helper)
• Salvages fix(telegram): preserve DM topic routing via reply fallback #22053 — preserves @leehack's commit and authorship
• Supersedes fix(telegram): send Direct Messages topics with direct_messages_topic_id #21941 — @max_chad's PR proposed routing all DM topics via direct_messages_topic_id, which works for true Bot API DM topics but does NOT work for Hermes-created topic lanes (those aren't classified as Direct Messages topics in incoming updates). fix(telegram): preserve DM topic routing via reply fallback #22053's three-case framing handles both. Credit to @max_chad for first identifying the post-Bot-API-10.0 regression and prototyping the routing change.

Attribution

@leehack's email (jhin.lee@unity3d.com) is added to AUTHOR_MAP in #22409 (prerequisite, must merge first).

Test plan for review

1. Merge chore(release): add leehack to AUTHOR_MAP for PR #22053 salvage #22409 first (AUTHOR_MAP).
2. Read the diff: 7 files changed, 1370 insertions, 153 deletions.
3. Run focused tests as above.
4. (Optional) Live-test on a real Telegram bot in a private DM topic lane — message the bot in a topic, verify the response stays in the topic lane instead of leaking to "All Messages."