swarm-ui: drop the wanted menu's two dead options, and two stale test headers

showDestroy and portal were each passed by one caller, the old card and the old
table cell, and neither exists now. Two test headers still named the detail
panel.

frontend/packages/swarm-ui/test/agent-permissions.test.mjs

@@ -1,4 +1,4 @@
-// The detail panel's permissions editor: its starting selection and the
+// An opened agent card's permissions editor: its starting selection and the
 // summary line. Run by `npm test` with Node's type stripping.
 import assert from "node:assert/strict";
 import { test } from "node:test";