test(acl,e2e): live diploma-upload coverage (refs #103)

- ACL integration test: stores a real document against a published Diploma
  informatieobjecttype and asserts it is persisted (bestandsnaam, informatieobjecttype,
  bestandsomvang) and related to the zaak.
- e2e: the registration journey now selects a PDF and uploads it (setInputFiles)
  before the behandelaar step.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/e2e/registration.spec.ts

@@ -56,6 +56,11 @@ test('DigiD submit → public INGEDIEND → documenten → behandelaar goedkeurt
   // why we supply the documents here rather than right after submit, when the trigger would race the
   // wait and no-op. (S-10b turns this into a real file upload; here it is the trigger that unblocks
   // beoordeling.)
+  await page.setInputFiles('#diploma', {
+    name: 'diploma.pdf',
+    mimeType: 'application/pdf',
+    buffer: Buffer.from('%PDF-1.4 synthetic diploma\n'),
+  });
   await page.getByRole('button', { name: /documenten aanleveren/i }).click();
   await expect(page.getByText(/documenten zijn aangeleverd/i)).toBeVisible();