update rm deadcode

app/Integrations/Domain/Writers/DnsDomainWriter.php

@@ -16,17 +16,33 @@ class DnsDomainWriter
             return false;
         }
 
-        DB::table('dns_manager_domain')->updateOrInsert(
-            ['legacy_id' => $data->legacyId],
-            [
-                'domain_name' => $data->domainName,
-                'dns_manager_server_id' => $data->dnsManagerServerId,
-                'is_created' => $data->isCreated,
-                'plesk_id' => $data->pleskId,
-                'created_at' => $data->createdAt,
-                'updated_at' => $data->updatedAt,
-            ]
-        );
+        $attributes = [
+            'legacy_id' => $data->legacyId,
+            'domain_name' => $data->domainName,
+            'dns_manager_server_id' => $data->dnsManagerServerId,
+            'is_created' => $data->isCreated,
+            'plesk_id' => $data->pleskId,
+            'created_at' => $data->createdAt,
+            'updated_at' => $data->updatedAt,
+        ];
+
+        $existingId = DB::table('dns_manager_domain')->where('legacy_id', $data->legacyId)->value('id');
+
+        // A WHMCS-created placeholder (DnsDomainLinker) has legacy_id NULL and the same
+        // domain_name — adopt it instead of inserting a duplicate row that would strand
+        // dns_domain_user pointing at the empty placeholder while NS records attach here.
+        if (! $existingId && $data->domainName !== null) {
+            $existingId = DB::table('dns_manager_domain')
+                ->whereNull('legacy_id')
+                ->whereRaw('LOWER(domain_name) = ?', [mb_strtolower($data->domainName)])
+                ->value('id');
+        }
+
+        if ($existingId) {
+            DB::table('dns_manager_domain')->where('id', $existingId)->update($attributes);
+        } else {
+            DB::table('dns_manager_domain')->insert($attributes);
+        }
 
         return true;
     }

app/Integrations/Whmcs/DTOs/ProductCategoryData.php

@@ -6,6 +6,7 @@ class ProductCategoryData
 {
     public function __construct(
         public readonly int $legacyId,
+        public readonly ?int $adoptId,
         public readonly string $name,
         public readonly string $slug,
         public readonly ?string $type,

app/Integrations/Whmcs/Support/SlugUniquifier.php

@@ -5,7 +5,6 @@ namespace App\Integrations\Whmcs\Support;
 use Illuminate\Support\Facades\DB;
 use Illuminate\Support\Str;
 
-/** Slugifies a candidate and appends -N until it's unique in the given column, excluding the row's own legacy_id. */
 class SlugUniquifier
 {
     public function unique(string $table, string $column, string $candidate, int $legacyId): string
@@ -14,10 +13,27 @@ class SlugUniquifier
         $slug = $base;
         $suffix = 1;
 
-        while (DB::table($table)->where($column, $slug)->where('legacy_id', '!=', $legacyId)->exists()) {
+        while ($this->ownedByAnotherRow($table, $column, $slug, $legacyId)) {
             $slug = "{$base}-" . ++$suffix;
         }
 
         return $slug;
     }
+
+    public function adoptableId(string $table, string $column, string $candidate): ?int
+    {
+        $slug = Str::slug($candidate) ?: 'item';
+
+        return DB::table($table)->where($column, $slug)->whereNull('legacy_id')->value('id');
+    }
+
+    private function ownedByAnotherRow(string $table, string $column, string $slug, int $legacyId): bool
+    {
+        return DB::table($table)
+            ->where($column, $slug)
+            ->where(function ($query) use ($legacyId) {
+                $query->whereNull('legacy_id')->orWhere('legacy_id', '!=', $legacyId);
+            })
+            ->exists();
+    }
 }

app/Integrations/Whmcs/Transformers/ProductCategoryTransformer.php

@@ -17,11 +17,17 @@ class ProductCategoryTransformer
         $row = (array) $row;
         $legacyId = (int) $row['id'];
         $name = $row['name'] ?: "WHMCS Group {$legacyId}";
+        $candidate = $row['slug'] ?: $name;
+
+        $adoptId = $this->slugs->adoptableId('product_categories', 'slug', $candidate);
 
         return new ProductCategoryData(
             legacyId: $legacyId,
+            adoptId: $adoptId,
             name: $name,
-            slug: $this->slugs->unique('product_categories', 'slug', $row['slug'] ?: $name, $legacyId),
+            slug: $adoptId
+                ? (Str::slug($candidate) ?: 'item')
+                : $this->slugs->unique('product_categories', 'slug', $candidate, $legacyId),
             type: $this->guessType($name),
             isActive: ! $row['hidden'],
             sortOrder: (int) $row['order'],

app/Integrations/Whmcs/Writers/ProductCategoryWriter.php

@@ -10,8 +10,9 @@ class ProductCategoryWriter
     public function write(ProductCategoryData $data): void
     {
         DB::table('product_categories')->updateOrInsert(
-            ['legacy_id' => $data->legacyId],
+            $data->adoptId ? ['id' => $data->adoptId] : ['legacy_id' => $data->legacyId],
             [
+                'legacy_id' => $data->legacyId,
                 'name' => $data->name,
                 'slug' => $data->slug,
                 'type' => $data->type,