panel-notifications: Account, Server > Settings, Server > Health, help; e2e

The pages of the mockups accepted in 87fa0a4, built from the kit's partials
(written by a Sonnet agent into the working tree, reviewed here):

- Account: "Send me notifications" in the Profile form, saved with the
  profile; an unticked box is off.
- Server > Settings: the instance switch (box 03), and box 04 Notification
  mail with the DKIM and SPF records of the server's own name, drawn with the
  record partial of a domain's DNS page and checked in DNS. Sending rate
  limits are box 02 in the left column. A record that is not in place is
  tagged as a warning, not a failure: notifications are sent without it.
- Server > Health: card 06 Notification mail with the state of each record
  and a link to Settings, beside Configuration (07); part of the polled
  fragment; Re-check DNS forces it too. Overview does not run this check.
- help.go: the Notifications topic and the clauses in Settings and Your
  account, word for word with help.html.

If the server's key cannot be read the pages still render: the DKIM record
is left out and SPF is shown unchecked.

e2e: the administrator gets a mailbox behind the sink and the server's DKIM
record from Settings is published; the level-2 refusal of the next step must
then arrive as a notification from postmaster@mail.e2e.test, signed as that
name with the key Settings shows, and must not be a row of the Outbound log.
The rotation step now waits for Postfix to be running: it follows a step that
restarts the container, and logrotate's `postfix reload` failed in between.

On the test server, for this tree: go vet clean, go test ./... 23 packages
ok, make e2e ok (147 s); the notification reached the sink 28 s after the
refusal.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/plans/panel-notifications.md

@@ -112,8 +112,8 @@ to the owner before any code ([panel-redesign.md](panel-redesign.md)
 - [x] Sending: local submission from `postmaster@<hostname>`, message text (`sendmail` as the panel user; signed through `non_smtpd_milters` with a key of the server's own name; no link in the text - the panel does not know its own address)
 - [x] Background checker: DNS, certificate, queue; the rules of *When a message is sent*
 - [x] Level-2 refusal event (from the `rejected` rows of the send log, looked at every minute)
-- [ ] Panel: Account, Settings, Health check, help
+- [x] Panel: Account, Settings, Health card, help
 - [x] guide.md, architecture.md, security.md, schema-migrations.md
-- [ ] `go vet`, `go test`, e2e: an event reaches a mailbox once and clears once
+- [x] `go vet`, `go test`, e2e: a level-2 refusal reaches a mailbox as a signed notification (on the test server: vet ok, 23 packages ok, e2e ok; "once" and "clears" are held by the unit tests of `internal/notify`)
 - [ ] Technical review
 - [ ] Security review

docs/roadmap.md

@@ -35,7 +35,7 @@ in `git log` and [CHANGELOG.md](../CHANGELOG.md).
 | template-data-typing | Typed structs for template data instead of `map[string]any` | candidate | — | — |
 | structured-logging | `log/slog` with levels and fields | candidate | — | — |
 | review-2026-08-followups | Remaining findings of the 2026-08-19 code review | candidate | — | — |
-| panel-notifications | E-mail notifications about important events | in progress | 6/10 | [plans/panel-notifications.md](plans/panel-notifications.md) |
+| panel-notifications | E-mail notifications about important events | in progress | 8/10 | [plans/panel-notifications.md](plans/panel-notifications.md) |
 | delivery-log-storage | Keep a message's `mail.log` lines with its send-log row | shipped `2.2.0` | 8/8 | [plans/delivery-log-storage.md](plans/delivery-log-storage.md) |
 | password-reset | Password reset by e-mail | candidate | — | — |
 | phone-desktop-mode | A phone browser in "desktop site" mode gets the phone navigation | candidate | — | — |