message page: a row the sweep closed says the panel closed it (stage 2b)

The History step of every bounced row said the receiving server refused
the message permanently or Postfix gave up, "the reason is in the delivery
log below" - for a row the reconcile sweep closed (reason "reconcile")
neither is known and the log has nothing (review of stage 1). Such a row's
step is now "Closed by the panel - Postfix no longer held the message and
mail.log never said what became of it ... rather than show a delivery it
cannot evidence." The help topic log names the case (design df96690).
Pictured for the owner with the real templates (dev/shots); the variant has
no mockup screen of its own, as the refused one.

Test: the page of a row the sweep closed says "Closed by the panel" and not
"the receiving server refused".

CHANGELOG [Unreleased], audit plan line ticked, roadmap 29/62.
Evidence: the message-page tests of ./internal/web/handlers ok locally; the
server run follows before the push.

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

CHANGELOG.md

@@ -33,6 +33,11 @@ Format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); version
   the page shows it. A row refused before this says the line was not kept.
   A refusal's line is red for a permanent reply, amber for a temporary one
   (audit 2026-10-12, stage 2b).
+- **A message the panel closed itself says so.** The history of a `bounced`
+  row read "the receiving server refused the message permanently, or
+  Postfix gave up ... The reason is in the delivery log below" also for a
+  row the reconcile sweep closed, where neither is known and the log has
+  nothing. Such a row's step is now "Closed by the panel", with why.
 - **The Sender check card counts connections and messages apart.** What was
   one column, "Messages deferred", was two things: connections Postfix
   turned away while the panel did not answer - refused before any message