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/CategoryExclusion.php

@@ -0,0 +1,100 @@
+<?php
+declare(strict_types=1);
+
+namespace ROITheme\Shared\Domain\ValueObjects;
+
+/**
+ * Value Object: Exclusion por categoria
+ *
+ * Evalua si un post pertenece a alguna de las categorias excluidas.
+ * Soporta matching por slug o term_id.
+ *
+ * @package ROITheme\Shared\Domain\ValueObjects
+ */
+final class CategoryExclusion extends ExclusionRule
+{
+    /**
+     * @param array<int|string> $excludedCategories Lista de slugs o IDs de categorias
+     */
+    public function __construct(
+        private readonly array $excludedCategories = []
+    ) {}
+
+    /**
+     * {@inheritdoc}
+     *
+     * Contexto esperado:
+     * - categories: array<array{term_id: int, slug: string, name: string}>
+     */
+    public function matches(array $context): bool
+    {
+        if (!$this->hasValues()) {
+            return false;
+        }
+
+        $postCategories = $context['categories'] ?? [];
+
+        if (empty($postCategories)) {
+            return false;
+        }
+
+        foreach ($postCategories as $category) {
+            // Buscar por slug
+            if (in_array($category['slug'], $this->excludedCategories, true)) {
+                return true;
+            }
+
+            // Buscar por term_id
+            if (in_array($category['term_id'], $this->excludedCategories, true)) {
+                return true;
+            }
+
+            // Buscar por term_id como string (para comparaciones flexibles)
+            if (in_array((string) $category['term_id'], $this->excludedCategories, true)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    public function hasValues(): bool
+    {
+        return !empty($this->excludedCategories);
+    }
+
+    public function serialize(): string
+    {
+        return json_encode($this->excludedCategories, JSON_UNESCAPED_UNICODE);
+    }
+
+    /**
+     * @return array<int|string>
+     */
+    public function getExcludedCategories(): array
+    {
+        return $this->excludedCategories;
+    }
+
+    /**
+     * Crea instancia desde JSON
+     */
+    public static function fromJson(string $json): self
+    {
+        $decoded = json_decode($json, true);
+
+        if (!is_array($decoded)) {
+            return self::empty();
+        }
+
+        return new self($decoded);
+    }
+
+    /**
+     * Crea instancia vacia
+     */
+    public static function empty(): self
+    {
+        return new self([]);
+    }
+}