feat: add attachment relationship to ProductVariant model and database schema

app/Domains/Catalog/Models/ProductVariant.php

@@ -2,10 +2,12 @@
 
 namespace App\Domains\Catalog\Models;
 
+use App\Domains\Attachable\Models\Attachment;
 use Illuminate\Database\Eloquent\Attributes\Fillable;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\Relations\BelongsToMany;
 use Illuminate\Database\Eloquent\Relations\HasMany;
 
 #[Fillable([
@@ -46,4 +48,17 @@ class ProductVariant extends Model
     {
         return $this->hasMany(ProductVariantDefinition::class, 'producto_variante_id');
     }
+
+    /**
+     * @return BelongsToMany<Attachment, $this>
+     */
+    public function attachments(): BelongsToMany
+    {
+        return $this->belongsToMany(
+            Attachment::class,
+            'variantes_attachments',
+            'variante_id',
+            'attachment_id'
+        )->withTimestamps();
+    }
 }