The gmail-triage skill's Telegram inline buttons emit callback_data of the
form `gt:<verb>:<arg>`, but `_handle_callback_query` had no `gt:` branch —
taps fell through silently and the spinner sat there until Telegram timed it
out.
Add `_handle_gmail_triage_callback`, dispatched from the existing callback
router, that:
- Authorizes the caller via the same `_is_callback_user_authorized` path as
the approval / slash-confirm / clarify handlers.
- Maps each verb to a script under `~/.hermes/scripts/gmail-triage/` and runs
it async with a 60s timeout.
- Splits verbs into one-shots (send / archive / draft / spam) — append the
confirmation and strip the keyboard so the action can't fire twice — and
sticky-state changes (mute / trust / vip ± -domain) — append the
confirmation but leave the keyboard tappable so the user can stack actions
on one email.
- On failure: toast only, keyboard preserved so the user can retry.
- Logs every callback outcome to gateway.log for debugging.