feat(purchase): add Purchase and PurchaseItem models with migrations for compras and compra_items tables

app/Domains/Purchase/Models/PurchaseItem.php

@@ -0,0 +1,54 @@
+<?php
+
+namespace App\Domains\Purchase\Models;
+
+use App\Domains\Catalog\Models\ProductVariant;
+use Illuminate\Database\Eloquent\Attributes\Fillable;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+
+#[Fillable([
+    'compra_id',
+    'producto_variante_id',
+    'cantidad',
+    'precio_unitario',
+    'discount_total',
+    'tax_total',
+    'total',
+])]
+class PurchaseItem extends Model
+{
+    use HasFactory;
+
+    protected $table = 'compra_items';
+
+    protected function casts(): array
+    {
+        return [
+            'compra_id' => 'integer',
+            'producto_variante_id' => 'integer',
+            'cantidad' => 'integer',
+            'precio_unitario' => 'decimal:2',
+            'discount_total' => 'decimal:2',
+            'tax_total' => 'decimal:2',
+            'total' => 'decimal:2',
+        ];
+    }
+
+    /**
+     * @return BelongsTo<Purchase, $this>
+     */
+    public function purchase(): BelongsTo
+    {
+        return $this->belongsTo(Purchase::class, 'compra_id');
+    }
+
+    /**
+     * @return BelongsTo<ProductVariant, $this>
+     */
+    public function variant(): BelongsTo
+    {
+        return $this->belongsTo(ProductVariant::class, 'producto_variante_id');
+    }
+}