test(e2e): pin the Audiobookshelf default listener grant

spec 24- signs in through SSO as qa-e2e — an identity in no Audiobookshelf
group — and must land inside the app with type "user". It is the counterpart
to 23-, which pins the admin escalation: together they catch both directions
of a scope-mapping regression (household locked out, or household made site
admin). Verified red against the pre-change mapping — the identity never
received a token — and green after re-provisioning: 4 passed.

Joined to the standard project, which is the only project whose identity
observes the default.

tests/e2e/specs/24-audiobookshelf-sso-default-listener.spec.ts

@@ -0,0 +1,53 @@
+import { expect, test } from "@playwright/test";
+
+// Audiobookshelf grants the LISTENER role to anyone the IdP lets sign in (2026-11-03).
+//
+// The role used to come from membership of `audiobookshelf_users` — a group nobody was ever
+// added to. The household accounts exist in authentik, and every one of them was denied at ABS
+// AFTER a successful authentication, which reads as a broken login rather than a policy decision.
+// The scope mapping now answers `abs_groups: ["user"]` for every signer and reserves `admin` for
+// `audiobookshelf_admins`, so the IdP is the only gate to the library and onboarding a listener
+// is exactly "create the account".
+//
+// This is the counterpart to 23-: that spec proves the admin escalation, this one proves the
+// DEFAULT grant, from an identity in neither group. Against the old mapping it is red — ABS
+// refuses the sign-in and the SPA never leaves /login.
+const HOST = "192.168.0.235:8000";
+const ABS = `http://${HOST}/audiobookshelf`;
+
+test("an SSO signer in no Audiobookshelf group lands as a listener", async ({ page }) => {
+  test.setTimeout(180_000);
+
+  await page.goto(`${ABS}/login`, { waitUntil: "domcontentloaded" });
+  const sso = page.getByText("Sign in with Authentik");
+  await expect(sso).toBeVisible();
+  await sso.click();
+
+  // The standard project's storageState carries a live authentik session, so the round trip is
+  // silent: authorize -> code -> callback -> token. Still being on /login means the app refused
+  // the identity (the denial this change removes) or the exchange failed.
+  await expect
+    .poll(() => !new URL(page.url()).pathname.endsWith("/login"), { timeout: 90_000 })
+    .toBe(true);
+
+  const grabToken = () =>
+    page.evaluate(() => {
+      for (let i = 0; i < localStorage.length; i++) {
+        const v = localStorage.getItem(localStorage.key(i) as string) || "";
+        if (/^[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+$/.test(v)) return v;
+      }
+      const c = document.cookie.match(/(?:^|;\s*)abs_token=([^;]+)/);
+      return c ? decodeURIComponent(c[1]) : "";
+    });
+  await expect.poll(grabToken, { timeout: 60_000 }).not.toBe("");
+
+  const me = await page.request.get(`${ABS}/api/me`, {
+    headers: { Authorization: `Bearer ${await grabToken()}` },
+  });
+  expect(me.status()).toBe(200);
+  const user = await me.json();
+  expect(user.username).toBe("qa-e2e");
+  // The default, not a grant: the listener role for a signer in neither group. Being `user`
+  // rather than `admin` is also the proof that the default never escalates.
+  expect(user.type).toBe("user");
+});