Fase 1: Estructura Base y DI Container - Clean Architecture

COMPLETADO: Fase 1 de la migración a Clean Architecture + POO

## Estructura de Carpetas
- ✓ Estructura completa de 4 capas (Domain, Application, Infrastructure, Presentation)
- ✓ Carpetas de Use Cases (SaveComponent, GetComponent, DeleteComponent, SyncSchema)
- ✓ Estructura de tests (Unit, Integration, E2E)
- ✓ Carpetas de schemas y templates

## Composer y Autoloading
- ✓ PSR-4 autoloading configurado para ROITheme namespace
- ✓ Autoloader optimizado regenerado

## DI Container
- ✓ DIContainer implementado con patrón Singleton
- ✓ Métodos set(), get(), has() para gestión de servicios
- ✓ Getters específicos para ComponentRepository, ValidationService, CacheService
- ✓ Placeholders que serán implementados en Fase 5
- ✓ Prevención de clonación y deserialización

## Interfaces
- ✓ ComponentRepositoryInterface (Domain)
- ✓ ValidationServiceInterface (Application)
- ✓ CacheServiceInterface (Application)
- ✓ Component entity placeholder (Domain)

## Bootstrap
- ✓ functions.php actualizado con carga de Composer autoloader
- ✓ Inicialización del DIContainer
- ✓ Helper function roi_container() disponible globalmente

## Tests
- ✓ 10 tests unitarios para DIContainer (100% cobertura)
- ✓ Total: 13 tests unitarios, 28 assertions
- ✓ Suite de tests pasando correctamente

## Validación
- ✓ Script de validación automatizado (48/48 checks pasados)
- ✓ 100% de validaciones exitosas

La arquitectura base está lista para la Fase 2.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/Infrastructure/DI/DIContainer.php

@@ -0,0 +1,153 @@
+<?php
+
+declare(strict_types=1);
+
+namespace ROITheme\Infrastructure\DI;
+
+use ROITheme\Domain\Component\ComponentRepositoryInterface;
+use ROITheme\Application\Contracts\ValidationServiceInterface;
+use ROITheme\Application\Contracts\CacheServiceInterface;
+
+/**
+ * Dependency Injection Container
+ *
+ * Singleton container that manages all service instances.
+ * Provides centralized access to dependencies throughout the application.
+ *
+ * @package ROITheme\Infrastructure\DI
+ */
+final class DIContainer
+{
+    private static ?DIContainer $instance = null;
+
+    /** @var array<string, object> */
+    private array $services = [];
+
+    /**
+     * Private constructor to prevent direct instantiation
+     */
+    private function __construct()
+    {
+        // Initialize services here
+    }
+
+    /**
+     * Get singleton instance
+     *
+     * @return self
+     */
+    public static function getInstance(): self
+    {
+        if (self::$instance === null) {
+            self::$instance = new self();
+        }
+
+        return self::$instance;
+    }
+
+    /**
+     * Prevent cloning
+     */
+    private function __clone()
+    {
+    }
+
+    /**
+     * Prevent unserialization
+     *
+     * @throws \Exception
+     */
+    public function __wakeup(): void
+    {
+        throw new \Exception('Cannot unserialize singleton');
+    }
+
+    /**
+     * Get Component Repository
+     *
+     * @return ComponentRepositoryInterface
+     */
+    public function getComponentRepository(): ComponentRepositoryInterface
+    {
+        if (!isset($this->services['component_repository'])) {
+            // Placeholder - will be replaced in Phase 5
+            throw new \RuntimeException('ComponentRepository not implemented yet. Will be available in Phase 5.');
+        }
+
+        return $this->services['component_repository'];
+    }
+
+    /**
+     * Get Validation Service
+     *
+     * @return ValidationServiceInterface
+     */
+    public function getValidationService(): ValidationServiceInterface
+    {
+        if (!isset($this->services['validation_service'])) {
+            // Placeholder - will be replaced in Phase 5
+            throw new \RuntimeException('ValidationService not implemented yet. Will be available in Phase 5.');
+        }
+
+        return $this->services['validation_service'];
+    }
+
+    /**
+     * Get Cache Service
+     *
+     * @return CacheServiceInterface
+     */
+    public function getCacheService(): CacheServiceInterface
+    {
+        if (!isset($this->services['cache_service'])) {
+            // Placeholder - will be replaced in Phase 5
+            throw new \RuntimeException('CacheService not implemented yet. Will be available in Phase 5.');
+        }
+
+        return $this->services['cache_service'];
+    }
+
+    /**
+     * Register a service
+     *
+     * @param string $key Service identifier
+     * @param object $service Service instance
+     * @return void
+     */
+    public function set(string $key, object $service): void
+    {
+        $this->services[$key] = $service;
+    }
+
+    /**
+     * Check if service exists
+     *
+     * @param string $key Service identifier
+     * @return bool
+     */
+    public function has(string $key): bool
+    {
+        return isset($this->services[$key]);
+    }
+
+    /**
+     * Get a service by key
+     *
+     * @param string $key Service identifier
+     * @return object|null
+     */
+    public function get(string $key): ?object
+    {
+        return $this->services[$key] ?? null;
+    }
+
+    /**
+     * Reset container (useful for testing)
+     *
+     * @return void
+     */
+    public static function reset(): void
+    {
+        self::$instance = null;
+    }
+}