feat: extract auth into @marketplaces/auth package, add backoffice admin provisioning spec

- ADR-0001: decision to extract auth/payment into shared @marketplaces/* packages
- Scaffold packages/auth, packages/payment; @marketplaces/auth now holds the real
  telegram (customer+admin QR/session) and ed25519 (future admin challenge/response)
  auth implementation, pushed to sources.vitanova.network/sdarbinyan/vitanovaPackages
- Rewire ~30 call sites to import from @marketplaces/auth; delete migrated originals
  from core/auth, core/admin-auth, services/, models/
- Replace environment coupling with AUTH_API_URL/TELEGRAM_BOT_USERNAME injection
  tokens and isDevMode(); wired as file:packages/auth pending registry publish
- Add TRACK-S §8: bootstrap per-marketplace admin login + marketplace-scoped
  sub-admin invite/role endpoints
- Build, arch:check:boundaries, and full test suite (103/103) all green

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

src/app/pages/cart/cart.component.ts

@@ -3,7 +3,8 @@ import { DecimalPipe } from '@angular/common';
 import { Router, RouterLink } from '@angular/router';
 import { FormsModule } from '@angular/forms';
 import { DomSanitizer, SafeResourceUrl } from '@angular/platform-browser';
-import { CartService, ApiService, LanguageService, AuthService } from '../../services';
+import { CartService, ApiService, LanguageService } from '../../services';
+import { AuthService } from '@marketplaces/auth';
 import { Item, CartItem, DeliveryOption } from '../../models';
 import { EMPTY, interval, of, Subscription } from 'rxjs';
 import { catchError, exhaustMap, take, timeout } from 'rxjs/operators';