log tailer: expiry, Postfix's time values and refusal lines as Postfix writes them

Expiry (assumptions A-8). Postfix 3.7.11 logs the end of a message's queue
lifetime once per message, "<id>: from=<..>, status=expired, returned to
sender" (src/qmgr/qmgr_active.c, qmgr_active_done_25_generic()), with no
line per recipient; the tailer waited for "to=..., status=expired", which
no Postfix writes, and the sweep closed only queued rows, so such rows
stayed deferred. The tailer now reads qmgr's line (ExpireMessage: each
recipient's newest open row of the id becomes bounced); the sweep closes a
deferred row too when Postfix no longer holds the message, and counts as
missed only a final line (sent, bounced, expiry). The queue listing's '#'
(forced expiry, showq_compat.c showq_message()) is read as a flag (B-PQ1).

Time values (B-PQ10, B-PQ11): conv_time() ported - one number, one
lower-case unit, the parameter's default unit when none (get_def_time_unit:
d for the lifetimes, h for delay_warning_time), the rest ignored; postconf
-h -x expands $name; bounce_queue_lifetime capped at maximal_queue_lifetime
as qmgr_post_init() caps it, so LongestLifetime is the queue lifetime.

Refusals (A-21, A-23, A-24, A-15): smtpd_whatsup() ends the NOQUEUE line
with sasl_username=<login> on an authenticated session; the line is now
matched to its row by client, login and sender, and a line without a login
is no application's. The client= line's login ends at the comma. The
"IPv6:" trim goes (namaddr is built from state->addr). A row recovered from
cleanup's line says that line names the last recipient only.

Stand (2026-10-14, make e2e, exit 0): new expired_message_is_closed -
defer_transports=smtp makes the retry service defer the message, postsuper
-e and postqueue -i force its expiry; mail.log has "<id>:
from=<alerts@sender.e2e.test>, status=force-expired, returned to sender"
and the row goes deferred -> bounced; refusals_show_postfixs_line passes
with the login match. go vet and go test ./... pass on the server.

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

test/e2e/main_test.go

@@ -345,6 +345,9 @@ func TestE2E(t *testing.T) {
 
 	// From here on the installation is no longer the one the run started: it
 	// is restored from its own backup, then switched to accept mail on port 25.
+	run("expired_message_is_closed", func(t *testing.T) {
+		testExpiredMessageIsClosed(t, sc)
+	})
 	run("full_backup_restore", func(t *testing.T) {
 		testFullBackupRestore(t, sc)
 	})