HomeChannel normalization covers env and YAML homes, but cron
`deliver: discord:<link>` targets and thread metadata reach the adapter as
written and still died in int(). Share one helper
(gateway.config.discord_channel_id_from_link) between HomeChannel and the
resolver every outbound Discord target passes through; message links and
non-link strings keep their existing error path. Tests trimmed to two
invariants: config load (env + YAML) and the resolver entry point.
c060a821d5