Owner Administration is complete. Summary of this final stretch of work:
Seed data extended with an inactive staff member, a pending invitation, a redeemed-reward fixture, a service with no eligible staff, and a future-appointment fixture for conflict testing — all idempotent, verified against the dev DB.
Testing brought to 179 unit / 86 integration / 27 E2E tests, all passing together on a freshly seeded, disposable Postgres:
Unit tests for every new pure validator (business hours, categories/services, booking rules, loyalty config, staff creation).
Integration tests covering opening-hours conflicts, last-owner protection, staff deactivation/eligibility conflicts, loyalty redemption's atomic race-guard, and owner-vs-barber/business-isolation authorization — all against a real Postgres.
12 new Playwright owner journeys, which surfaced and fixed two genuine issues along the way: a cookie-clearing race condition in the sign-out-mid-test flow (a real, reproducible timing bug, not just a test artifact), and confirmation that seed fixtures upserted by deterministic ID go stale once "today" has moved on — now handled defensively.
Desktop responsiveness: converted the single-column Business Details, Booking Rules, and Loyalty Configuration forms to a genuine two-column layout at the lg: breakpoint (verified via measured element positions, not just screenshots), confirmed mobile stacking is unaffected.
Final verification: clean tsc, eslint, and next build, plus the full three-suite run against one fresh database as the authoritative pass.