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/ControllerTest.template.php

@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Unit\{{Namespace}};
+
+use PHPUnit\Framework\TestCase;
+use PHPUnit\Framework\Attributes\Test;
+use Mockery;
+use Illuminate\Http\Request;
+use Symfony\Component\HttpFoundation\Response;
+use {{TargetClassFullName}};
+
+class {{ClassName}}Test extends TestCase
+{
+    private {{ClassName}} $controller;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        // $this->controller = new {{ClassName}}(...);
+    }
+
+    protected function tearDown(): void
+    {
+        Mockery::close();
+        parent::tearDown();
+    }
+
+    #[Test]
+    public function it_returns_successful_response(): void
+    {
+        // Arrange
+        // $request = Request::create('/api/resource', 'GET');
+
+        // Act
+        // $response = $this->controller->index($request);
+
+        // Assert
+        // $this->assertSame(Response::HTTP_OK, $response->getStatusCode());
+        $this->assertTrue(true);
+    }
+}