feat(exclusions): Implement component exclusion system (Plan 99.11)

Adds ability to exclude components from specific:
- Categories (by slug or term_id)
- Post/Page IDs
- URL patterns (substring or regex)

Architecture:
- Domain: Value Objects (CategoryExclusion, PostIdExclusion,
  UrlPatternExclusion, ExclusionRuleSet) + Contracts
- Application: EvaluateExclusionsUseCase +
  EvaluateComponentVisibilityUseCase (orchestrator)
- Infrastructure: WordPressExclusionRepository,
  WordPressPageContextProvider, WordPressServerRequestProvider
- Admin: ExclusionFormPartial (reusable UI),
  ExclusionFieldProcessor, JS toggle

The PageVisibilityHelper now uses the orchestrator UseCase that
combines page-type visibility (Plan 99.10) with exclusion rules.

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

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

Shared/Domain/ValueObjects/ExclusionRule.php

@@ -0,0 +1,37 @@
+<?php
+declare(strict_types=1);
+
+namespace ROITheme\Shared\Domain\ValueObjects;
+
+/**
+ * Clase base abstracta para reglas de exclusion
+ *
+ * Define el contrato comun para todos los tipos de exclusion.
+ * Cada implementacion concreta define su logica de matching.
+ *
+ * @package ROITheme\Shared\Domain\ValueObjects
+ */
+abstract class ExclusionRule
+{
+    /**
+     * Evalua si el contexto actual coincide con la regla
+     *
+     * @param array<string, mixed> $context Contexto de la pagina actual
+     * @return bool True si el contexto coincide (debe excluirse)
+     */
+    abstract public function matches(array $context): bool;
+
+    /**
+     * Verifica si la regla tiene valores configurados
+     *
+     * @return bool True si hay valores configurados
+     */
+    abstract public function hasValues(): bool;
+
+    /**
+     * Serializa los valores para almacenamiento
+     *
+     * @return string JSON string
+     */
+    abstract public function serialize(): string;
+}