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/take.rs

@@ -0,0 +1,13 @@
+use fedserv_api::{Sender, ServiceCtx, Store};
+
+// TAKE <id> (aka ASSIGN): claim a specific ticket.
+pub fn handle(me: &str, from: &Sender, id: Option<&str>, ctx: &mut ServiceCtx, db: &mut dyn Store) {
+    if !super::require_oper(me, from, ctx) {
+        return;
+    }
+    let Some(n) = id.and_then(|n| n.parse::<u64>().ok()) else {
+        ctx.notice(me, from.uid, "Syntax: TAKE <id>");
+        return;
+    };
+    super::take_id(me, from, n, ctx, db);
+}