feat: implement multi-tenant cart system with stock reservation and inventory tracking

database/migrations/2026_07_01_160000_add_stock_real_and_stock_reservado_to_productos_variantes_table.php

@@ -0,0 +1,36 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::table('productos_variantes', function (Blueprint $table) {
+            $table->renameColumn('stock', 'stock_real');
+        });
+
+        Schema::table('productos_variantes', function (Blueprint $table) {
+            $table->unsignedInteger('stock_reservado')->default(0)->after('stock_real');
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::table('productos_variantes', function (Blueprint $table) {
+            $table->dropColumn('stock_reservado');
+        });
+
+        Schema::table('productos_variantes', function (Blueprint $table) {
+            $table->renameColumn('stock_real', 'stock');
+        });
+    }
+};