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>

internal/web/view/help.go

@@ -256,7 +256,7 @@ var serverTopics = []HelpTopic{
 			Br(), Br(),
 			"Each user turns notifications on or off under Account and needs an e-mail there; Server › Settings turns them off for everyone. They are the panel's own mail: not rows of the Outbound log, and not counted against any limit.",
 			Br(), Br(),
-			"For that mail to arrive, the server's own name needs two DNS records of its own, as each of your domains does: a DKIM key, which the panel generates and signs notifications with, and an SPF record, ", Code("v=spf1 a -all"), ". Server › Settings gives both with the values to publish, and Server › Health shows whether they are in place. Without them notifications are still sent, and a receiver may file them as spam. Mail of your domains does not depend on either."),
+			"For that mail to arrive, the server's own name needs two DNS records of its own, as each of your domains does: a DKIM key, which the panel generates and signs notifications with, and an SPF record, ", Code("v=spf1 a -all"), ". Server › Settings gives both with the values to publish and whether they are in place, and its Re-check DNS checks them again once they are published; Server › Health shows them too. Without them notifications are still sent, and a receiver may file them as spam. Mail of your domains does not depend on either."),
 	}},
 }