parity(api,apps): security hotfix stage 2 - real customer sessions, close IDOR

Stage 1 narrowed GET /customers but did not close the leak: the response still
carried every customer id, and /customers/:id, /:id/orders and
/:id/ledger-entries were still public, so the full customer book was still two
requests away. The user caught this. Stage 2 deletes the id-bearing surface.

Customer JWT, separate from the admin one (T1):
  - new src/modules/customer-auth/ with its own passport strategy,
    CustomerJwtGuard, @CustomerAuth() and @CurrentCustomer()
  - signed with JWT_CUSTOMER_SECRET, and every token carries typ:'customer'
    which the strategy verifies; both checks are present deliberately
  - customer state re-read per request, so deactivating takes effect at once
  - mirrors the reference's own split: auth:api vs auth('api-customer')

Real OTP (D6), porting ApiMobileController::userAuth/userVerfiy (:39-64):
  - new CustomerOtp table, additive migration, nothing existing touched
  - parity behaviour: rand(1000,9999), active-customer filter, faTOen digit
    normalisation on both number and code, rejection on mismatch
  - approved improvements over the reference: bcrypt-hashed code, 2-minute
    expiry, 5 attempts then lockout, single use, send throttle (60s per
    number, 5/number and 20/IP per 10 min), and no number enumeration

Routes removed, replaced by token-derived equivalents:
  GET customers, customers/:id, /:id/orders, /:id/ledger-entries
    -> GET customer/me, customer/me/orders, customer/me/ledger-entries
No route accepts a customer id any more, so the IDOR is closed structurally
rather than by a check. The admin panel was unaffected (admin/customers-omde/*).

Both apps migrated in the same commit per the v1/v2 parity rule: token-based
session store, Bearer header, 401 -> clear session and route to login, real
two-step OTP login. Each app keeps its own markup and styling; only logic moved.

Tests: auth-smoke.sh extended with the stage-2 assertions, 46 passed 0 failed
against a live server. jest installed dev-only (user-approved) so pnpm test
works for the first time: 7 passed covering faToEn, which moved to its own
digits.ts to be testable without booting Nest. Typecheck clean on api,
user-app and user-app-v2; both apps build.

[ref: henza_server ApiMobileController.php:39-78]

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

apps/api/src/modules/customer-auth/customer-auth.module.ts

@@ -0,0 +1,25 @@
+import { Module } from '@nestjs/common';
+import { JwtModule } from '@nestjs/jwt';
+import { PassportModule } from '@nestjs/passport';
+import { PrismaModule } from '../../prisma/prisma.module';
+import { CustomersModule } from '../customers/customers.module';
+import { CustomerAuthController } from './customer-auth.controller';
+import { CustomerAuthService } from './customer-auth.service';
+import { CustomerJwtStrategy } from './customer-jwt.strategy';
+
+/**
+ * Customer session, deliberately separate from AuthModule (admins).
+ *
+ * JwtModule is registered without a secret here: the customer secret is passed
+ * per-call in CustomerAuthService.verifyOtp, and CustomerJwtStrategy reads it
+ * directly, so an admin secret can never sign a customer token by accident.
+ *
+ * No APP_GUARD is registered — customer routes opt in with @CustomerAuth().
+ */
+@Module({
+  imports: [PrismaModule, PassportModule, JwtModule.register({}), CustomersModule],
+  controllers: [CustomerAuthController],
+  providers: [CustomerAuthService, CustomerJwtStrategy],
+  exports: [CustomerAuthService],
+})
+export class CustomerAuthModule {}