Split HelpServ into one file per command

REQUEST/CANCEL/LIST/VIEW/TAKE/NEXT/CLOSE each move to their own file;
the oper guard and the shared claim helper stay in lib.rs beside the
dispatcher. No behaviour change.

modules/helpserv/src/list.rs

@@ -0,0 +1,24 @@
+use fedserv_api::{Sender, ServiceCtx, Store};
+
+// LIST [ALL]: operators list the open queue (or every ticket with ALL).
+pub fn handle(me: &str, from: &Sender, arg: Option<&str>, ctx: &mut ServiceCtx, db: &mut dyn Store) {
+    if !super::require_oper(me, from, ctx) {
+        return;
+    }
+    let open_only = !arg.is_some_and(|a| a.eq_ignore_ascii_case("ALL"));
+    let tickets = db.help_tickets(open_only);
+    if tickets.is_empty() {
+        ctx.notice(me, from.uid, if open_only { "No open tickets." } else { "No tickets." });
+        return;
+    }
+    for t in &tickets {
+        let state = match (&t.handler, t.open) {
+            (_, false) => " (closed)".to_string(),
+            (Some(h), true) => format!(" (taken by {h})"),
+            (None, true) => String::new(),
+        };
+        let short: String = t.message.chars().take(60).collect();
+        ctx.notice(me, from.uid, format!("\x02#{}\x02 {} — {}{}", t.id, t.requester, short, state));
+    }
+    ctx.notice(me, from.uid, format!("{} ticket(s). \x02VIEW\x02 <id> for detail.", tickets.len()));
+}