fix(e2e): judge only body-carrying script responses in the ABS SSO spec

A 304 carries no Content-Type by spec, and the OIDC bounce revalidates the entry script (Cache-Control: max-age=0 + ETag), so the blanket MIME assertion failed on a healthy bundle. The HTML-stub class is still caught: 200s are still judged, and the count floor now runs on the same filtered set.

tests/e2e/specs/23-audiobookshelf-sso.spec.ts

@@ -26,11 +26,11 @@ test("SSO round trip boots the SPA and grants a real Audiobookshelf session", as
 }) => {
   test.setTimeout(180_000);
 
-  const scripts: { url: string; type: string }[] = [];
+  const scripts: { url: string; type: string; status: number }[] = [];
   page.on("response", (res) => {
     const u = new URL(res.url());
     if (u.host === HOST && u.pathname.endsWith(".js")) {
-      scripts.push({ url: u.pathname, type: res.headers()["content-type"] ?? "" });
+      scripts.push({ url: u.pathname, type: res.headers()["content-type"] ?? "", status: res.status() });
     }
   });
 
@@ -59,8 +59,11 @@ test("SSO round trip boots the SPA and grants a real Audiobookshelf session", as
   // Defect 1 gate: nothing the app loaded may be HTML dressed as a script. The render proof
   // is the SSO button above — it only exists once the bundle has executed, so no DOM-shape
   // guess is needed (the shell's own mount markup says nothing about whether it booted).
-  expect(scripts.length, "the SPA loaded no JavaScript").toBeGreaterThan(2);
-  for (const s of scripts) {
+  // Only responses that carried a body can be judged: the OIDC bounce re-validates the entry
+  // script (Cache-Control: max-age=0 + ETag) and a 304 carries no Content-Type by spec.
+  const bodies = scripts.filter((s) => s.status === 200);
+  expect(bodies.length, "the SPA loaded no JavaScript").toBeGreaterThan(2);
+  for (const s of bodies) {
     expect(s.type, `${s.url} arrived as ${s.type}`).toContain("javascript");
   }