Implement localization for API responses and error messages

- Added localization support for API responses in English and Spanish.
- Introduced a middleware to set the API locale based on the Accept-Language header.
- Updated various exception messages and validation responses to use localized strings.
- Created new language files for English and Spanish translations.
- Refactored existing code to replace hardcoded messages with localized strings.
- Added tests to verify localization functionality and response correctness.

tests/Feature/Auth/LoginControllerTest.php

@@ -35,7 +35,9 @@ class LoginControllerTest extends TestCase
 
         $response
             ->assertOk()
-            ->assertJsonPath('message', 'Sesion iniciada correctamente.')
+            ->assertHeader('Content-Language', 'es')
+            ->assertJsonPath('code', 'auth.login_success')
+            ->assertJsonPath('message', 'Sesión iniciada correctamente.')
             ->assertJsonPath('token_type', 'Bearer')
             ->assertJsonPath('user.id', $user->id)
             ->assertJsonPath('user.nombre_apellido', 'Grace Hopper')
@@ -85,7 +87,8 @@ class LoginControllerTest extends TestCase
         $this->withHeader('Authorization', 'Bearer '.$token)
             ->postJson('/api/logout')
             ->assertOk()
-            ->assertJsonPath('message', 'Sesion cerrada correctamente.');
+            ->assertJsonPath('code', 'auth.logout_success')
+            ->assertJsonPath('message', 'Sesión cerrada correctamente.');
 
         $this->assertDatabaseCount('personal_access_tokens', 0);
     }
@@ -118,6 +121,34 @@ class LoginControllerTest extends TestCase
         ]);
     }
 
+    public function test_it_localizes_success_and_validation_responses_from_accept_language(): void
+    {
+        $tenant = $this->createTenant('acme');
+        User::query()->create([
+            'nombre_apellido' => 'Grace Hopper',
+            'email' => 'grace@example.com',
+            'password' => Hash::make('secret123'),
+        ]);
+
+        $this->withHeader('Accept-Language', 'en-US,en;q=0.9')
+            ->postJson('/api/login', [
+                'email' => 'grace@example.com',
+                'password' => 'secret123',
+                'tenant_codigo' => $tenant->codigo,
+            ])
+            ->assertOk()
+            ->assertHeader('Content-Language', 'en')
+            ->assertJsonPath('code', 'auth.login_success')
+            ->assertJsonPath('message', 'Signed in successfully.');
+
+        $this->withHeader('Accept-Language', 'en')
+            ->postJson('/api/login', [])
+            ->assertUnprocessable()
+            ->assertHeader('Content-Language', 'en')
+            ->assertJsonPath('errors.email.0', 'The email field is required.')
+            ->assertJsonPath('errors.password.0', 'The password field is required.');
+    }
+
     public function test_it_replaces_the_active_user_cart_with_the_guest_cart_on_login(): void
     {
         $tenant = $this->createTenant('acme');

tests/Feature/Integration/TenantIntegrationControllerTest.php

@@ -31,7 +31,7 @@ class TenantIntegrationControllerTest extends TestCase
                     Mockery::on(fn (Integration $argument) => $argument->is($integration)),
                     ['api_key' => 'secret']
                 )
-                ->andReturn(new TenantIntegration());
+                ->andReturn(new TenantIntegration);
         });
 
         $this->postJson('/api/test-tenant/integrations/test_integration', [
@@ -40,7 +40,8 @@ class TenantIntegrationControllerTest extends TestCase
             ],
         ])->assertOk()
             ->assertExactJson([
-                'message' => 'integration configured correctly',
+                'code' => 'integration.configured',
+                'message' => 'Integración configurada correctamente.',
             ]);
     }
 }

tests/Feature/Localization/ApiLocalizationTest.php

@@ -0,0 +1,40 @@
+<?php
+
+namespace Tests\Feature\Localization;
+
+use Tests\TestCase;
+
+class ApiLocalizationTest extends TestCase
+{
+    public function test_it_negotiates_spanish_from_accept_language(): void
+    {
+        $this->withHeader('Accept-Language', 'es-AR,es;q=0.9')
+            ->postJson('/api/login')
+            ->assertUnprocessable()
+            ->assertHeader('Content-Language', 'es')
+            ->assertJsonPath('errors.email.0', 'El campo email es obligatorio.')
+            ->assertJsonPath('errors.password.0', 'El campo contraseña es obligatorio.');
+    }
+
+    public function test_it_negotiates_english_from_accept_language(): void
+    {
+        $this->withHeader('Accept-Language', 'en-US,en;q=0.9')
+            ->postJson('/api/login')
+            ->assertUnprocessable()
+            ->assertHeader('Content-Language', 'en')
+            ->assertJsonPath('errors.email.0', 'The email field is required.')
+            ->assertJsonPath('errors.password.0', 'The password field is required.');
+    }
+
+    public function test_it_localizes_framework_error_responses(): void
+    {
+        $this->withHeader('Accept-Language', 'en')
+            ->getJson('/api/route-that-does-not-exist')
+            ->assertNotFound()
+            ->assertHeader('Content-Language', 'en')
+            ->assertJson([
+                'code' => 'errors.not_found',
+                'message' => 'The requested resource was not found.',
+            ]);
+    }
+}