feat: add comprehensive unit testing support for CakePHP

- Add 4 CakePHP Claude Code skills: cakephp-unit-test, cakephp-test-setup, cakephp-test-review, cakephp-mock-helper
- Add 11 CakePHP PHPUnit component templates (Table, Entity, Controller, Service, Command, Component, Middleware, Mailer, Form, Behavior, Helper)
- Add CakePHP configs (phpunit.xml.dist, app_local.test.php for SQLite in-memory)
- Add comprehensive CakePHP documentation and component guides
- Update test-runner.sh and installer to auto-detect Laravel and CakePHP
- Add CakePHP CI/CD templates for GitHub Actions and GitLab CI
- Update system prompt, verification checklist, and README with dedicated guides

templates/cakephp/phpunit/MailerTest.template.php

@@ -0,0 +1,45 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Test\TestCase\Mailer;
+
+use App\Mailer\{{MAILER_NAME}}Mailer;
+use Cake\TestSuite\EmailTrait;
+use Cake\TestSuite\TestCase;
+
+/**
+ * App\Mailer\{{MAILER_NAME}}Mailer Test Case
+ */
+class {{MAILER_NAME}}MailerTest extends TestCase
+{
+    use EmailTrait;
+
+    /**
+     * Test subject
+     *
+     * @var \App\Mailer\{{MAILER_NAME}}Mailer
+     */
+    protected {{MAILER_NAME}}Mailer ${{VARIABLE_NAME}};
+
+    /**
+     * setUp method
+     */
+    protected function setUp(): void
+    {
+        parent::setUp();
+        $this->{{VARIABLE_NAME}} = new {{MAILER_NAME}}Mailer();
+    }
+
+    /**
+     * Test send welcome email
+     */
+    public function testSendWelcomeEmail(): void
+    {
+        // Act
+        $this->{{VARIABLE_NAME}}->send('welcome', ['user@example.com', 'John Doe']);
+
+        // Assert
+        $this->assertMailSentTo('user@example.com');
+        $this->assertMailContainsText('John Doe');
+    }
+}