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/Concerns/Markable.php

@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Models\Concerns;
+
+use App\Models\Tag;
+use Illuminate\Database\Eloquent\Builder;
+use Illuminate\Database\Eloquent\Relations\MorphToMany;
+
+trait Markable
+{
+    public function initializeMarkable(): void
+    {
+        $this->mergeCasts(['is_starred' => 'boolean']);
+    }
+
+    public function tags(): MorphToMany
+    {
+        return $this->morphToMany(Tag::class, 'taggable')->orderBy('tags.title');
+    }
+
+    /**
+     * @param array<string, mixed> $filters
+     */
+    public function scopeMarked(Builder $query, array $filters): Builder
+    {
+        $tagIds = array_values(array_filter(array_map('intval', (array) ($filters['tag_ids'] ?? []))));
+
+        return $query
+            ->when(
+                filter_var($filters['starred'] ?? false, FILTER_VALIDATE_BOOL),
+                fn (Builder $q) => $q->where($this->qualifyColumn('is_starred'), true),
+            )
+            ->when($tagIds, fn (Builder $q) => $q->whereHas('tags', fn (Builder $tags) => $tags->whereIn('tags.id', $tagIds)));
+    }
+}