feat: complete Smartgift AI Laravel unit testing toolkit

- Add 10 core testing guides (setup, AAA principles, PHPUnit/Pest, mocking, anti-patterns, PHP 8.4+, debugging, data factories, advanced edge cases)
- Add 13 component testing guides covering all Laravel layers
- Add standard templates for PHPUnit 10/11 and Pest v2/v3 including ArchitectureTest
- Add Docker smart test runner, dependency installer, and CI/CD templates (GitHub Actions, GitLab CI)
- Add 4 Claude Code skills (laravel-test-setup, laravel-unit-test with --all mode, laravel-test-review, laravel-mock-helper)
- Add single unified installer script (sg-install-unit-testing.sh) with global support, CLI runners, and 1-click updater (sg-test-update)
- Add comprehensive documentation (README.md, USAGE-GUIDE.md)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

templates/phpunit/MiddlewareTest.template.php

@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Unit\{{Namespace}};
+
+use Tests\TestCase;
+use PHPUnit\Framework\Attributes\Test;
+use Illuminate\Http\Request;
+use Symfony\Component\HttpFoundation\Response;
+use {{TargetClassFullName}};
+
+class {{ClassName}}Test extends TestCase
+{
+    private {{ClassName}} $middleware;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        $this->middleware = new {{ClassName}}();
+    }
+
+    #[Test]
+    public function it_passes_request_to_next_closure_when_authorized(): void
+    {
+        // Arrange
+        $request = Request::create('/test-route', 'GET');
+        $nextCalled = false;
+
+        $next = function ($req) use (&$nextCalled) {
+            $nextCalled = true;
+            return response('OK', Response::HTTP_OK);
+        };
+
+        // Act
+        $response = $this->middleware->handle($request, $next);
+
+        // Assert
+        $this->assertTrue($nextCalled);
+        $this->assertSame(Response::HTTP_OK, $response->getStatusCode());
+    }
+}