feat: product screenshots gallery

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

app/Models/ProductScreenshot.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Casts\Attribute;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+
+class ProductScreenshot extends Model
+{
+    protected $fillable = ['product_id', 'path', 'position'];
+
+    public function product(): BelongsTo
+    {
+        return $this->belongsTo(Product::class);
+    }
+
+    protected function url(): Attribute
+    {
+        return Attribute::get(fn () => asset('storage/'.$this->path));
+    }
+}