logtail: the sweep closes only queued rows, with reason "reconcile" (audit H3)

reconcile() closed a row through UpdateStatus (WHERE queue_id AND to_addr),
which could overwrite a "sent" the tailer wrote between the listing and the
close, and rewrite an old row of a reused queue id. store.CloseUnreported
sets status bounced and reason "reconcile" (store.ReasonReconcile; the
0006 column, no schema change) WHERE ... AND status = 'queued'; the sweep
counts rows actually closed.

Tests: store - a queued row is closed with the reason, a sent row is left
alone (0 rows); logtail - the sweep's close goes through CloseUnreported.

CHANGELOG [Unreleased], audit plan line ticked, roadmap 9/61.
Evidence: go vet ./... clean; go test ./internal/store ok, ./internal/logtail
ok but for TestFollowTailsAndRotates (Windows rename of an open file, fails
here always); the server run of the stage follows before the push.

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

CHANGELOG.md

@@ -15,6 +15,12 @@ Format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); version
   marked `bounced`. A listing over the cap now tells the sweep nothing, as it
   already did for the notification about mail waiting too long; the Mail
   queue page still shows the cut listing with its note (audit 2026-10-12, H3).
+- **The sweep closes only what is still queued, and says it did.** Its close
+  was the tailer's plain status update, so a `sent` the log wrote an instant
+  earlier could be overwritten with `bounced`, and a reused queue id could
+  rewrite an old row of the same recipient. The close is now conditional on
+  the row still being `queued`, and the row it closes carries the reason
+  `reconcile` (audit 2026-10-12, H3).
 
 ## [2.4.2] - 2026-10-14