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>

.gitignore

@@ -2,6 +2,7 @@
 
 # Compiled output
 /dist
+packages/*/dist
 /tmp
 /out-tsc
 /bazel-out