Phase 6

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.

src/features/staff/components/working-hours-form.tsx

@@ -6,6 +6,8 @@ import { Button } from "@/components/ui/button";
 import { Switch } from "@/components/ui/switch";
 import { Weekday } from "@/generated/prisma/enums";
 import { saveWorkingHoursAction } from "../actions/working-hours";
+import type { WorkingHoursActionResult } from "../actions/working-hours";
+import type { WorkingHoursDayInput } from "@/services/staff/staff.service";
 
 const DAY_ORDER: Weekday[] = [
   Weekday.MONDAY,
@@ -52,7 +54,16 @@ export interface InitialWorkingHoursRow {
   endMinutes: number | null;
 }
 
-export function WorkingHoursForm({ initialRows, businessHoursLabel }: { initialRows: InitialWorkingHoursRow[]; businessHoursLabel: Record<Weekday, string> }) {
+export function WorkingHoursForm({
+  initialRows,
+  businessHoursLabel,
+  onSave = saveWorkingHoursAction,
+}: {
+  initialRows: InitialWorkingHoursRow[];
+  businessHoursLabel: Record<Weekday, string>;
+  /** Owner-on-behalf-of-staff editing (src/app/(owner)/owner/team/[id]/hours) injects its own Server Action here instead of the self-service default — same pattern as AppointmentStatusActions' `actions` prop. */
+  onSave?: (days: WorkingHoursDayInput[]) => Promise<WorkingHoursActionResult>;
+}) {
   const router = useRouter();
   const [days, setDays] = useState<DayState[]>(() =>
     DAY_ORDER.map((dayOfWeek) => {
@@ -84,7 +95,7 @@ export function WorkingHoursForm({ initialRows, businessHoursLabel }: { initialR
   const handleSave = () => {
     setError(null);
     startTransition(async () => {
-      const result = await saveWorkingHoursAction(
+      const result = await onSave(
         days.map((d) => ({
           dayOfWeek: d.dayOfWeek,
           isOff: d.isOff,