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/Support/Markables.php

@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Support;
+
+use App\Models\Customer;
+use App\Models\Invoice;
+use App\Models\Order;
+use App\Models\Service;
+use Illuminate\Database\Eloquent\Model;
+
+final class Markables
+{
+    /**
+     * @var array<string, array{model: class-string<Model>, key: string, permission: string}>
+     */
+    public const TYPES = [
+        'services'  => ['model' => Service::class, 'key' => 'id', 'permission' => 'customer.edit'],
+        'customers' => ['model' => Customer::class, 'key' => 'uuid', 'permission' => 'customer.edit'],
+        'orders'    => ['model' => Order::class, 'key' => 'id', 'permission' => 'order.edit'],
+        'invoices'  => ['model' => Invoice::class, 'key' => 'id', 'permission' => 'invoice.edit'],
+    ];
+
+    public static function find(string $type, string $key): Model
+    {
+        $definition = self::TYPES[$type];
+
+        return $definition['model']::query()->where($definition['key'], $key)->firstOrFail();
+    }
+}