Initial commit: Horux Backend API

- API REST para gestion de facturas electronicas mexicanas (CFDI)
- Laravel 9 con autenticacion OAuth 2.0 (Passport)
- Integracion con Syntage, Clerk y Facturama
- 30 modelos Eloquent, 39 controladores
- Documentacion completa en /docs

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/Http/Middleware/ValidateSignature.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace App\Http\Middleware;
+
+use Illuminate\Routing\Middleware\ValidateSignature as Middleware;
+
+class ValidateSignature extends Middleware
+{
+    /**
+     * The names of the query string parameters that should be ignored.
+     *
+     * @var array<int, string>
+     */
+    protected $except = [
+        // 'fbclid',
+        // 'utm_campaign',
+        // 'utm_content',
+        // 'utm_medium',
+        // 'utm_source',
+        // 'utm_term',
+    ];
+}