Implement browser-based e2e tests covering:
- Tests 1-5: Stats progression (cohort, feed, eggs, moves, backdating)
- Test 6: Event viewing and deletion UI
- Test 7: Harvest outcomes with yield items
- Test 8: Optimistic lock selection validation
Includes page objects for reusable form interactions and fresh_db
fixtures for tests requiring isolated database state.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
