feat(admin): star/tags marks, service product-type filter, campaign bulk actions, SMTP test

- Star (is_starred) and colored tags for services, customers, orders, invoices:
  Markable trait, tags/taggables tables, PATCH administrator/marks/{type}/{key},
  tag CRUD, list filters starred / tag_ids[]
- GET administrator/services accepts product_type (falls back to product type
  for legacy rows without services.type)
- Mail campaigns: bulk cancel / retry failed / delete; cancelled campaigns are
  skipped by SendMailCampaignRecipient
- POST administrator/settings/test-smtp sends a test email through the saved
  mail transport

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

routes/api.php

@@ -31,6 +31,7 @@ Route::prefix('v1')
                 require __DIR__.'/api/admin/domains.php';
                 require __DIR__.'/api/admin/hosting.php';
                 require __DIR__.'/api/admin/system.php';
+                require __DIR__.'/api/admin/tags.php';
             });
         });