HostServ: temporary vhosts (expiry)

SET <account> <host> [duration] assigns a vhost that lapses after the
duration (e.g. 30d); a Vhost carries an optional expiry and the store hides
an expired one lazily (like a suspension), so it stops applying on identify/
ON without a sweep. LIST flags temporary vhosts.

hostserv/src/approve.rs

@@ -26,7 +26,7 @@ pub fn handle(me: &str, from: &Sender, args: &[&str], ctx: &mut ServiceCtx, net:
         ctx.notice(me, from.uid, format!("Rejected \x02{account}\x02's vhost request."));
         return;
     }
-    match db.set_vhost(account, &host, from.nick) {
+    match db.set_vhost(account, &host, from.nick, None) {
         Ok(()) => {
             for uid in net.uids_logged_into(account) {
                 ctx.apply_vhost(&uid, &host);