dns-record-collapse: a published record is drawn folded

The dns_record partial draws a record whose tag is "published" and that
has no "In DNS now" (Record.Folded) as a <details> whose summary is the
head - name, tag, "Show values" - with the host, type and value behind
it, as the mockup of fffee9c. Every other record stays a <div>, open.
One partial, so the outbound domain's page, the inbound domain's and
Settings › Notification mail change together; panel.css takes the
mockup's rules, help.go the help's sentence word for word.

Re-check DNS posts and redirects to the page, which is drawn from the
fresh check: a record that has just turned right comes back folded. No
page that draws records polls them, so nothing has to keep a fold open.

Tests: the dns_record partial folds only a published record and closes
the block it opened (TestDNSRecordFoldsOnlyWhenPublished); the mismatch
test reads the folded head. go vet + go test (26 packages) and make e2e
on the test server for this tree.

CHANGELOG [Unreleased]; roadmap row done, its section says what was
decided.

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

internal/web/view/help.go

@@ -157,7 +157,7 @@ var overviewTopics = []HelpTopic{
 
 var outboundTopics = []HelpTopic{
 	{ID: HelpDNS, Title: "DNS records", Body: []Text{
-		Rich("DKIM proves the message was signed by this relay, SPF lists the addresses allowed to send for the domain, DMARC tells receivers what to do when both fail and where to report. Publish all three exactly as shown; merge SPF into an existing record rather than adding a second one. A domain's status is the worst of its three records, and results are cached for a few minutes, so use Re-check DNS after publishing. The SPF check is shallow: it looks for this server's address in the record itself and does not follow ",
+		Rich("DKIM proves the message was signed by this relay, SPF lists the addresses allowed to send for the domain, DMARC tells receivers what to do when both fail and where to report. Publish all three exactly as shown; merge SPF into an existing record rather than adding a second one. A domain's status is the worst of its three records, and results are cached for a few minutes, so use Re-check DNS after publishing. A record DNS already holds as shown is folded to its name and status; Show values opens it to copy them again. The SPF check is shallow: it looks for this server's address in the record itself and does not follow ",
 			Code("include:"), " or ", Code("redirect="), ", so a record that relies on them is reported as a warning, not a failure. ",
 			Code("p=none"), " does not affect delivery; tighten to ", Code("quarantine"), ", then ", Code("reject"),
 			", once the reports look clean. A domain's report address is set in its Domain settings."),