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/Services/SocialAccountsService.php

@@ -0,0 +1,47 @@
+<?php
+namespace App\Services;
+
+use App\Models\User;
+use App\Models\LinkedSocialAccount;
+use Laravel\Socialite\Two\User as ProviderUser;
+use Illuminate\Support\Facades\File;
+
+class SocialAccountsService
+{
+    /**
+     * Find or create user instance by provider user instance and provider name.
+     *
+     * @param ProviderUser $providerUser
+     * @param string $provider
+     *
+     * @return User
+     */
+    public function findOrCreate(ProviderUser $providerUser, string $provider): User
+    {
+        $linkedSocialAccount = LinkedSocialAccount::where('provider_name', $provider)
+            ->where('provider_id', $providerUser->getId())
+            ->first();
+        if ($linkedSocialAccount) {
+            return $linkedSocialAccount->user;
+        } else {
+            $user = null;
+            if ($email = $providerUser->getEmail()) {
+                $user = User::where('email', $email)->first();
+            }
+            if (! $user) {
+                $user = User::create([
+                    'name' => $providerUser->getName(),
+                    'email' => $providerUser->getEmail(),
+                    //'rfc' = $providerUser->public_metadata->rfc,
+                    'social_id' => $providerUser->getId() . '_' . $provider
+                ]);
+                $user->save();
+            }
+            $user->linkedSocialAccounts()->create([
+                'provider_id' => $providerUser->getId(),
+                'provider_name' => $provider
+            ]);
+            return $user;
+        }
+    }
+}