Close: make side-effects best-effort so none can abort the commit+delete

runFinalClose ran the transcript archive, creator DM, close log, and closure
email in the same try as the close transition and channel delete, with the
transcript posted *before* the commit. A failure in any of them (notably a
DiscordAPIError 50001 Missing Access when posting the transcript to the archive
channel) aborted the whole close: the customer saw 'ticket closed' but the DB
stayed open and the channel was never deleted.

Rewrite so the close transition + pendingDelete commit FIRST, each side-effect is
individually best-effort via a closeStep wrapper, and scheduleTicketChannelDelete
always runs. finalizeForceClose was already commit-first; wrap its remaining
unguarded archiving send too.

handlers/commands/close.js

@@ -94,7 +94,8 @@ async function finalizeForceClose(channelRef, clientRef, _TicketModel, _recordAc
         .catch(err => logError('gmailLabels: resolved move', err).catch(() => {}));
     }
 
-    await enqueueSend(channelRef, 'Ticket force-closed. Archiving...');
+    // Both best-effort — a failure here must not skip the channel delete below.
+    await enqueueSend(channelRef, 'Ticket force-closed. Archiving...').catch(() => {});
     await postTranscript(channelRef, clientRef, freshTicket).catch(tErr =>
       console.error('Transcript error (force-close):', tErr)
     );