feat(api): implement javascript-first architecture for cache compatibility

- Add REST endpoint GET /roi-theme/v1/adsense-placement/visibility
- Add Domain layer: UserContext, VisibilityDecision, AdsenseSettings VOs
- Add Application layer: CheckAdsenseVisibilityUseCase
- Add Infrastructure: AdsenseVisibilityChecker, Controller, Enqueuer
- Add JavaScript controller with localStorage caching
- Add test plan for production validation

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Public/AdsensePlacement/Domain/Contracts/AdsenseVisibilityCheckerInterface.php

@@ -0,0 +1,26 @@
+<?php
+declare(strict_types=1);
+
+namespace ROITheme\Public\AdsensePlacement\Domain\Contracts;
+
+use ROITheme\Public\AdsensePlacement\Domain\ValueObjects\UserContext;
+use ROITheme\Public\AdsensePlacement\Domain\ValueObjects\VisibilityDecision;
+
+/**
+ * Interface para el servicio que evalua visibilidad de anuncios.
+ *
+ * Domain Layer - Define el contrato sin dependencias de infraestructura.
+ *
+ * @package ROITheme\Public\AdsensePlacement\Domain\Contracts
+ */
+interface AdsenseVisibilityCheckerInterface
+{
+    /**
+     * Evalua si los anuncios deben mostrarse para el contexto dado.
+     *
+     * @param int $postId ID del post (0 para paginas de archivo/home)
+     * @param UserContext $userContext Contexto del usuario
+     * @return VisibilityDecision Decision con razones y cache
+     */
+    public function check(int $postId, UserContext $userContext): VisibilityDecision;
+}