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>

app/Models/Invoice.php

@@ -3,6 +3,7 @@
 namespace App\Models;
 
 use App\Enums\Invoice\InvoiceStatus;
+use App\Models\Concerns\Markable;
 use App\Traits\LogsActivity;
 use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
@@ -11,7 +12,7 @@ use Illuminate\Database\Eloquent\SoftDeletes;
 
 class Invoice extends Model
 {
-    use HasFactory, SoftDeletes, LogsActivity;
+    use HasFactory, SoftDeletes, LogsActivity, Markable;
 
     protected $table = 'invoices';