Mail is content: a state's mail: and the invite mail, published for gdo

`mail: { to, subject, body }` on a state in aggregates.yaml sends when a
record enters that state, `to: submitter` or one address, templates
over the record's fields plus {site}, {chain}, {email}. An invite mails
its one-time link built in, reworded by `mail.invite` in site.yaml,
which also carries the sender (`mail.from`, `mail.reply_to`); without
it a site sends nothing and says so in the log. Portal renders the
text and an HTML alternative and publishes one message per state
change on portal.mail.send in the WORMHOLE stream, id <bucket>:<record>
:<state> so a retried transition sends once; uhhm/gdo holds the
durable consumer and talks SMTP. The lint requires a required email
field on every form recording into a bucket that mails the submitter.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01L4jrCgLiKKHAEFuZUJjckH

CHANGELOG.md

@@ -4,6 +4,10 @@ One line per change, grouped by the release that shipped it. Newest
 first. A release is a Cargo.toml bump plus a `v<version>` tag; the
 content repos pin the tag they run (see the end of this file).
 
+## 0.3.43 (2026-09-23)
+
+- Mail is content: `mail: { to, subject, body }` on a state in aggregates.yaml sends when a record enters that state (`to: submitter` or one address; `{field}`, `{site}`, `{chain}`, `{email}` in the templates), and an invite mails its one-time link built in; `site.yaml` gains `mail: { from, reply_to, invite }`. Portal renders and publishes on `portal.mail.send` in the `WORMHOLE` stream; uhhm/gdo delivers. The lint requires a required `email` field on every form recording into a bucket that mails the submitter.
+
 ## 0.3.42 (2026-09-23)
 
 - people: the Kanidm person lookup reads the body, since Kanidm 1.11 answers a missing person with 200 and `null` rather than 404; before this every invite skipped account creation and failed on the group step