- Replace hard-coded 'u1' user_id with per-test UUID to prevent PK collision on re-runs - Add @AfterEach null-safe cleanup for environments and users rows - Use containsExactlyInAnyOrder for enum assertions to catch misspelled names - Slug suffix on environment insert avoids slug uniqueness conflicts on re-runs Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>