- Create backend/tests/fixtures/cloud/nextcloud_expected_root.json with owner_confirmed: true and corrected 10-item name/kind manifest - Add test_nextcloud_expected_root_manifest: exact set and kind equality against fixture (T-12.1-19 — count-only acceptance blocked) - Update 12.1-VALIDATION.md: manifest status OWNER CONFIRMED, add exact-acceptance row to Nyquist matrix