notification-mail-recheck: Re-check DNS on Server › Settings

The owner, 2026-10-16: "Да, бери notification-mail-recheck". The records
of the server's own name can be checked again where they are shown: Re-
check DNS in Settings' page head (mockup 98e4dfc) posts to
POST /server/settings/dns-recheck (guard 52a9811), global role, which
runs Health's lookups - the server's address, then serverMail(true) - and
returns to /server/settings?rechecked=1, "DNS re-checked.". The
Notification mail box's end slot says when the records were checked
("The server's own name · checked 3 min ago", from the check's
CheckedAt; the old wording while nothing was looked up). A record that
has turned right comes back folded.

Tests: the page head's form and the end slot, and the Settings form
holding neither the re-check nor the right column
(TestSettingsRechecksTheMailRecords); the re-check skips the cache,
redirects and the page shows both records folded
(TestSettingsRecheckAsksForNotificationMailAgain); a domain
administrator gets 404 (globalOnlyRoutes). go vet + go test (26
packages) and make e2e on the test server for this tree.

Docs: architecture.md routes, the panel-redesign plan's route table,
guide § Settings, help (help.go word for word with the mockup's);
CHANGELOG [Unreleased]; roadmap row done. The roadmap's settings-save-row
note no longer claims the left-column form was needed for this - the
action went to the page head.

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

docs/architecture.md

@@ -797,7 +797,7 @@ only reads (the delete confirmation at `GET …/delete` renders a form).
 | Outbound › DMARC reports | `GET /outbound/dmarc` · `…/dmarc/domains/{id}` · `…/dmarc/reports/{id}` — registered only with `DMARC_REPORTS_ENABLE=true` |
 | Inbound › Domains | `GET, POST /inbound/domains` · `/inbound/domains/{id}` · `POST …/dns-recheck`, `…/upstream`, `…/recipients` · `GET, POST …/delete` — registered only with `INBOUND_RELAY_ENABLE=true` |
 | Inbound › Log, Filter lists | `GET /inbound/log` · `GET, POST /inbound/filter-lists` · `POST /inbound/filter-lists/{id}/delete` — registered only with `INBOUND_RELAY_ENABLE=true` |
-| Server | `GET /server/health` (+ `/fragment`) · `POST /server/health/recheck`, `/server/health/reload` · `GET /server/log` (+ `/fragment`) · `GET, POST /server/backup` · `POST /server/backup/import` · `/server/users`, `…/new`, `…/{uid}`, `…/{uid}/delete` · `GET, POST /server/settings` · `GET /server/components` |
+| Server | `GET /server/health` (+ `/fragment`) · `POST /server/health/recheck`, `/server/health/reload` · `GET /server/log` (+ `/fragment`) · `GET, POST /server/backup` · `POST /server/backup/import` · `/server/users`, `…/new`, `…/{uid}`, `…/{uid}/delete` · `GET, POST /server/settings` · `POST /server/settings/dns-recheck` · `GET /server/components` |
 | Account | `GET /account` · `POST /account/profile`, `/account/password` |
 | User menu | `GET /help` · `POST /logout` (public mux) |