OPT and Improved Installation Wizzard

1. Summary of changes
Password auth → email OTP, everywhere it existed for the tenant/business app: sign-in, customer self-registration (/register), staff-invitation acceptance, and the installer's administrator step. Flow is always: email → 6-digit code emailed → code entered → session created, via one shared service (otp.service.ts) reused by every entry point.
NextChair Manager's own auth was not touched — this only affects tenant-side (business admin/staff/customer) authentication, per the spec's explicit instruction.
Installer improvements: Step 2 (Administrator) now asks only Name + Email + optional Phone, verified inline via the same OTP widget (no redirect). Step 3 (Business Details) pre-fills Business Name from the Manager-provisioned BUSINESS_NAME, shows the booking URL (NEXT_PUBLIC_APP_URL) as a read-only info box instead of asking for it, and has a distinctly-labeled "Business Website (optional)" field with copy clarifying it's not the booking URL.
Installation cannot complete with an unverified admin email — enforced server-side (finalizeOtp runs inside the same DB transaction as user/business creation), not just trusted from client state. A mid-wizard refresh still can't create duplicate admins or partial records — that property was preserved by design, not incidentally.
2. Prisma/database changes
New EmailOtp model (email as PK — one row per address, so a new request naturally invalidates the previous code): codeHash, purpose, expiresAt, attempts, verifiedAt, consumedAt, timestamps. Only a bcrypt hash of the code is ever stored.
User.passwordHash — unchanged schema (already nullable), just annotated as deprecated. No destructive migration; historical rows are untouched.
Migration: prisma/migrations/20260905190022_email_otp_authentication — adds EmailOtp only. Generated and applied against throwaway containers only; the real next-chair-mysql production database was never touched (confirmed not even running on this host during this session).
3. New environment variables
None required for production. One new variable, E2E_TEST_MODE, exists purely for the Playwright suite (set only in playwright.config.ts's webServer.env) — it unlocks a /api/test/otp-code debug endpoint and bypasses OTP rate limiting so the same seeded users can sign in dozens of times across one test run. It must never be set on a real deployment; nothing in the app sets it anywhere else.

4. Email delivery configuration
Nothing new to configure. OTP emails reuse the existing EmailProvider abstraction and EMAIL_PROVIDER env var exactly as configured today — console in dev (prints to server logs), brevo in production via the same SMTP credentials already documented. The OTP email is a new template (otp-email.ts) sent directly (bypassing the async notification/cron pipeline, since a 10-minute-expiry code can't wait for a delivery retry loop).

5. Migration considerations for existing users/installations
Existing users lose password sign-in — the only way to authenticate now is email OTP. There is no in-app fallback; this is an intentional, sharp cutover. If existing customers/staff/admins need advance notice, that's a business/communications decision outside this change.
No account data is deleted or migrated — passwordHash rows are simply never read for auth anymore.
prisma/seed.ts / scripts/ensure-super-admin.ts still set a passwordHash for seeded dev users — harmless and vestigial now, not cleaned up (flagging it rather than touching seed data silently).
Installations already completed are unaffected; only new installer runs go through the OTP admin-verification step.
6. Files changed
New:

src/lib/auth/otp.service.ts — the core requestOtp/verifyOtp/finalizeOtp service
src/lib/auth/__tests__/otp.service.integration.test.ts
src/services/notifications/templates/otp-email.ts
src/features/auth/components/otp-code-step.tsx — shared code-entry UI
src/features/auth/actions/request-sign-in-otp.ts
src/app/api/test/otp-code/route.ts — e2e-only, gated on E2E_TEST_MODE
prisma/migrations/20260905190022_email_otp_authentication/
Modified — auth core: prisma/schema.prisma, src/auth.ts, src/features/auth/schemas.ts

Modified — sign-in/register/invitations: sign-in-form.tsx, register.ts, register-form.tsx, accept-invitation.ts, accept-invitation-form.tsx, staff-invitation.service.ts

Modified — installer: installer.service.ts, schema.ts, install.ts, install-wizard.tsx, install/page.tsx, installer.service.integration.test.ts

Modified — email / e2e infra: console-email-provider.ts, playwright.config.ts, e2e/helpers.ts, and the four e2e/*.spec.ts files (dropped the now-unused password argument from every signIn() call).

7. Verification performed
npx tsc --noEmit, npm run lint, npm test (276 unit) — all clean.
npm run test:integration (207 tests, throwaway DB) — includes 11 new OTP-service tests and a rewritten installer suite; a genuine race condition in requestOtp (concurrent requests for a brand-new email double-hitting the upsert's create branch) was caught and fixed here.
Full npm run test:e2e against a fresh throwaway database: 36/37 passed. The one failure (owner-journeys "opening hours conflict" test) is a pre-existing, auth-unrelated ordering flake — appointment-count ambiguity from earlier tests' bookings — not something this change touches or introduced.
Live manual verification in-browser: existing seeded customer sign-in via OTP; new customer registration via OTP (session created, landed on Home); installer wizard end-to-end through Step 3, confirming email-verification gating, Business Name pre-population from BUSINESS_NAME, and the read-only Booking URL / distinct Business Website fields.
All throwaway Docker containers/DBs used for this work have been removed; the real production database was never touched.

e2e/owner-journeys.spec.ts

@@ -32,7 +32,7 @@ test.describe.serial("owner administration journeys", () => {
   });
 
   test("1. owner sees a real, data-backed dashboard with configuration warnings", async ({ page }) => {
-    await signIn(page, SEEDED.owner.email, "password123");
+    await signIn(page, SEEDED.owner.email);
     await page.goto("/owner");
 
     // The Manage hub's H1 (see (owner)/owner/page.tsx) — Dashboard content
@@ -51,7 +51,7 @@ test.describe.serial("owner administration journeys", () => {
   });
 
   test("2. owner views the all-staff calendar, filters by staff, and switches to agenda", async ({ page }) => {
-    await signIn(page, SEEDED.owner.email, "password123");
+    await signIn(page, SEEDED.owner.email);
     await page.goto("/owner/calendar");
 
     await expect(page.getByRole("heading", { name: "Calendar" })).toBeVisible();
@@ -79,7 +79,7 @@ test.describe.serial("owner administration journeys", () => {
   });
 
   test("3. owner edits business details and the change persists", async ({ page }) => {
-    await signIn(page, SEEDED.owner.email, "password123");
+    await signIn(page, SEEDED.owner.email);
     await page.goto("/owner/settings/business");
 
     await expect(page.getByRole("heading", { name: "Business Details" })).toBeVisible();
@@ -100,7 +100,7 @@ test.describe.serial("owner administration journeys", () => {
   });
 
   test("4. owner tightens opening hours, reviews the appointment conflict, and saves anyway without cancelling it", async ({ page }) => {
-    await signIn(page, SEEDED.owner.email, "password123");
+    await signIn(page, SEEDED.owner.email);
 
     // Marcus and Leo each have a seeded future CONFIRMED appointment (see
     // prisma/seed.ts, appt-upcoming-confirmed / appt-leo-future). Those rows
@@ -158,7 +158,7 @@ test.describe.serial("owner administration journeys", () => {
   });
 
   test("5. owner adds a new barber and gets a dev invite link", async ({ page }) => {
-    await signIn(page, SEEDED.owner.email, "password123");
+    await signIn(page, SEEDED.owner.email);
     await page.goto("/owner/team/add");
 
     await expect(page.getByRole("heading", { name: "Add Staff" })).toBeVisible();
@@ -179,7 +179,7 @@ test.describe.serial("owner administration journeys", () => {
   });
 
   test("6. owner changes a barber's role and service eligibility", async ({ page }) => {
-    await signIn(page, SEEDED.owner.email, "password123");
+    await signIn(page, SEEDED.owner.email);
     await page.goto("/owner/team?q=Jamie");
     await page.getByRole("link", { name: /Jamie Wallace/ }).click();
 
@@ -212,7 +212,7 @@ test.describe.serial("owner administration journeys", () => {
   });
 
   test("7. owner creates a service category and service, visible immediately on the customer booking flow", async ({ page }) => {
-    await signIn(page, SEEDED.owner.email, "password123");
+    await signIn(page, SEEDED.owner.email);
     await page.goto("/owner/services");
     await expect(page.getByRole("heading", { name: "Services", exact: true })).toBeVisible();
 
@@ -239,7 +239,7 @@ test.describe.serial("owner administration journeys", () => {
   });
 
   test("8. owner requires booking approval, and a new customer booking reflects it immediately", async ({ page }) => {
-    await signIn(page, SEEDED.owner.email, "password123");
+    await signIn(page, SEEDED.owner.email);
     await page.goto("/owner/settings/booking-rules");
     await expect(page.getByRole("heading", { name: "Booking Rules" })).toBeVisible();
 
@@ -269,7 +269,7 @@ test.describe.serial("owner administration journeys", () => {
     await expect(page.getByText("Pending Approval")).toBeVisible();
 
     // Restore the seeded default so later journeys (and re-runs) see auto-confirmed bookings again.
-    await signIn(page, SEEDED.owner.email, "password123");
+    await signIn(page, SEEDED.owner.email);
     await page.goto("/owner/settings/booking-rules");
     await page.getByRole("switch", { name: "Require approval for new bookings" }).click();
     await page.getByRole("button", { name: "Save", exact: true }).click();
@@ -277,7 +277,7 @@ test.describe.serial("owner administration journeys", () => {
   });
 
   test("9. owner configures the loyalty programme", async ({ page }) => {
-    await signIn(page, SEEDED.owner.email, "password123");
+    await signIn(page, SEEDED.owner.email);
     await page.goto("/owner/settings/loyalty");
     await expect(page.getByRole("heading", { name: "Loyalty Programme" })).toBeVisible();
 
@@ -297,7 +297,7 @@ test.describe.serial("owner administration journeys", () => {
   });
 
   test("10. owner redeems a customer's available loyalty reward on an appointment", async ({ page }) => {
-    await signIn(page, SEEDED.owner.email, "password123");
+    await signIn(page, SEEDED.owner.email);
     await page.goto("/owner/calendar?view=agenda");
 
     // Seeded: Sam Osei has a CHECKED_IN appointment with Leo today, and sits
@@ -322,7 +322,7 @@ test.describe.serial("owner administration journeys", () => {
   });
 
   test("11. a barber without MANAGE_STAFF is denied access to owner administration", async ({ page }) => {
-    await signIn(page, SEEDED.barberHaircutOnly.email, "password123");
+    await signIn(page, SEEDED.barberHaircutOnly.email);
 
     await page.goto("/owner");
     await expect(page).toHaveURL(/\/staff$/);
@@ -331,7 +331,7 @@ test.describe.serial("owner administration journeys", () => {
   });
 
   test("12. the owner reaches barber tools straight from the merged nav — no mode switch", async ({ page }) => {
-    await signIn(page, SEEDED.owner.email, "password123");
+    await signIn(page, SEEDED.owner.email);
     await page.goto("/owner");
 
     // The old "Switch to Owner Admin"/"Switch to Barber Tools" links are
@@ -345,7 +345,7 @@ test.describe.serial("owner administration journeys", () => {
   });
 
   test("13. owner reports show real, data-backed appointment/service/staff/customer/loyalty/notification figures", async ({ page }) => {
-    await signIn(page, SEEDED.owner.email, "password123");
+    await signIn(page, SEEDED.owner.email);
     await page.goto("/owner");
     // "View Reports" was the old Dashboard footer's button label; Reports is
     // now one of the Manage hub's grouped sections (see (owner)/owner/page.tsx).