A managed cron with `deliver: "slack"` (no captured origin) delivers to the
Slack home channel, but the brief was never mirrored into that session and
the in_channel seed never fired: bare-platform targets resolved with no
`_resolved_from` provenance, so `_target_mirror_eligible` treated them like
`all` broadcast expansions.
- `_resolve_delivery_targets` derives `from_broadcast` from the raw token
and passes it to `_resolve_single_delivery_target`; a user-written bare
platform token is tagged `_resolved_from: "home"`, `all` expansions stay
untagged (fan-out is never continuable).
- `_target_mirror_eligible`: `home` eligible under the same flags as
`origin_fallback` (per-job attach_to_session wins, else cron.mirror_delivery).
- `_MIRROR_PROVENANCE_RANK`: `home` == `origin_fallback` so token order
through dedup cannot strip eligibility.
- Docs, tool schema text, cron/gateway AGENTS.md updated; existing
exact-dict pins carry the new key.
Squashed from PR #101819 (commits 5fe612c9, 65e36926, 10e0af1d, f2cc4639):
they predate the cron/scheduler.py -> scheduler_delivery.py split and do
not cherry-pick individually onto current main.
Victor Kyriazakos
22356075f1