swarm ui: show when an agent's claude login was stored, and delete it

The agent's settings get a claude login row: when the swarm stored the
login, read by the minter from the leaf's metadata, or that none is, with a
delete that removes every version after a confirmation. New minter steps
(status, delete), controller routes (GET claude-login, DELETE
claude-login/stored) and a read and delete grant on the leaf's metadata,
pinned in the module-eval check.

frontend/packages/swarm-ui/test/stored-login.test.mjs

@@ -0,0 +1,33 @@
+// The stored claude login's routes and wording. Run by `npm test`, which Node
+// runs with its built-in test runner and type stripping, so the `.ts` module
+// is imported as it is.
+import assert from "node:assert/strict";
+import { test } from "node:test";
+import {
+  deleteMessage,
+  deleteStoredLoginPath,
+  storedAtMs,
+  storedLoginPath,
+} from "../src/agent/claude-login/StoredLogin.ts";
+
+test("the routes name the agent, escaped", () => {
+  assert.equal(storedLoginPath("atlas"), "/api/agents/atlas/claude-login");
+  assert.equal(
+    deleteStoredLoginPath("atlas"),
+    "/api/agents/atlas/claude-login/stored",
+  );
+  assert.equal(storedLoginPath("a/b"), "/api/agents/a%2Fb/claude-login");
+});
+
+test("the time the store gives is read as an instant, or as nothing", () => {
+  assert.equal(
+    storedAtMs({ stored_at: "2026-11-09T20:00:00.123456789Z" }),
+    Date.parse("2026-11-09T20:00:00.123Z"),
+  );
+  assert.equal(storedAtMs({ stored_at: null }), null);
+  assert.equal(storedAtMs({ stored_at: "not a time" }), null);
+});
+
+test("the delete's confirmation names the agent", () => {
+  assert.match(deleteMessage("atlas"), /stored claude login for atlas/);
+});