NickServ: add UPDATE and LIST

UPDATE re-applies your auto-joins and vhost and re-checks for waiting
memos without re-identifying. LIST (auspex-gated) shows registered
accounts matching a glob, capped at 100. Adds an accounts_matching store
method.

modules/nickserv/src/update.rs

@@ -0,0 +1,21 @@
+use echo_api::{Sender, ServiceCtx, Store};
+
+// UPDATE: re-apply your account's auto-joins and vhost, and re-check for waiting
+// memos, without having to re-identify.
+pub fn handle(me: &str, from: &Sender, ctx: &mut ServiceCtx, db: &dyn Store) {
+    let Some(account) = from.account else {
+        ctx.notice(me, from.uid, "You need to be logged in. Identify to NickServ first.");
+        return;
+    };
+    for entry in db.ajoin_list(account) {
+        ctx.force_join(from.uid, &entry.channel, &entry.key);
+    }
+    if let Some(v) = db.vhost(account) {
+        ctx.apply_vhost(from.uid, &v.host);
+    }
+    let unread = db.unread_memos(account);
+    if unread > 0 {
+        ctx.notice(me, from.uid, format!("You have \x02{unread}\x02 new memo(s). Read them with \x02/msg MemoServ READ NEW\x02."));
+    }
+    ctx.notice(me, from.uid, "Your status has been refreshed.");
+}