One record answers another, from a list

Three small things that together make a board work: a link on every
listed record to a page about it (ResourceSpec.link, {id} and {field}
in the address); a state mail whose `to` is a field of the record this
one belongs to ({notice.email}), with that record's fields in the
text, and a lint that the form carries the record field it reaches
through; and value: "{user.email}" filled from the session and hidden,
so someone the site knows is not asked who they are.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GT37Z1Xtfd9pUuQtMTg6Yt

docs/state-machines.md

@@ -62,6 +62,13 @@ as text with an HTML alternative. `to: submitter` means the record's
 `email` field, and the lint then requires every form filling that
 bucket to collect a required `email`.
 
+A record that belongs to another (a `type: record` field, say
+`notice`) can write to that record's people: `to: "{notice.email}"`
+goes to whoever posted the notice, and `{notice.hva}` in the body is
+what they posted. The lint requires every form filling the bucket to
+carry that field. This is how an answer to a notice on a board reaches
+the neighbour who put it there, without anyone in between.
+
 Portal renders it and publishes on `portal.mail.send`. gdo delivers
 it, and a reply comes back on `portal.mail.received` as a note beside
 the record. A note never moves a case.