fix(acf): bootstrap Advanced Custom Fields integration

AdvancedCustomFields.php was procedural top-level add_action code; the
file was never loaded because Composer PSR-4 only autoloads class files
and it is not listed in autoload.files. As a result the ACF location
type was never registered and `page_type == <cpt>_page` rules always
evaluated to false on ACF Pro 6.x.

Refactor the file into a class-based integration consistent with the
existing Polylang/WordPressSeo/Wpml/Autodescription composites:

- Implement IntegrationInterface with isSupported() + registerHooks().
- Guard isSupported() on class_exists('ACF_Location_Page_Type') so the
  hook is only registered when ACF Pro's parent class is loaded.
- Register the integration in Container as a service factory.
- Add it to Plugin::getIntegrations() so plugin.php bootstraps it.
- Extend PluginTest and ContainerTest to cover the new integration.

Author: huubl

src/Container.php

@@ -10,6 +10,7 @@
 use n5s\PageForCustomPostType\Core\RewriteManager;
 use n5s\PageForCustomPostType\Frontend\Handler;
 use n5s\PageForCustomPostType\Frontend\QueryFilter;
+use n5s\PageForCustomPostType\Integration\AdvancedCustomFields;
 use n5s\PageForCustomPostType\Integration\Autodescription;
 use n5s\PageForCustomPostType\Integration\Polylang;
 use n5s\PageForCustomPostType\Integration\WordPressSeo;
@@ -141,6 +142,7 @@ public function __construct()
             ),
 
             // Integration composites
+            AdvancedCustomFields\AdvancedCustomFields::class => static fn (): AdvancedCustomFields\AdvancedCustomFields => new AdvancedCustomFields\AdvancedCustomFields(),
             Polylang\Polylang::class => fn (): Polylang\Polylang => new Polylang\Polylang(
                 $this->get(Polylang\UrlTranslation::class),
                 $this->get(Polylang\Translation::class),

src/Integration/AdvancedCustomFields/AdvancedCustomFields.php

@@ -4,14 +4,34 @@
 
 namespace n5s\PageForCustomPostType\Integration\AdvancedCustomFields;
 
-add_action('acf/include_location_rules', static function (int $acfMajorVersion): void {
-    if ($acfMajorVersion !== 5) {
-        return;
+use n5s\PageForCustomPostType\Integration\IntegrationInterface;
+
+/**
+ * Advanced Custom Fields integration composite.
+ *
+ * Registers a custom location type that exposes `<cpt>_page` values on the
+ * `page_type` rule, so field groups can target PFCPT-bound pages.
+ */
+final class AdvancedCustomFields implements IntegrationInterface
+{
+    public function isSupported(): bool
+    {
+        return \class_exists('ACF_Location_Page_Type');
+    }
+
+    public function registerHooks(): void
+    {
+        add_action('acf/include_location_rules', [$this, 'registerLocationRules']);
     }
 
-    require_once __DIR__ . '/LocationPageType.php';
+    public function registerLocationRules(int $acfFieldApiVersion): void
+    {
+        if ($acfFieldApiVersion !== 5) {
+            return;
+        }
 
-    $store = acf_get_store('location-types');
-    $locationType = new LocationPageType();
-    $store->set($locationType->name, $locationType);
-});
+        $store = acf_get_store('location-types');
+        $locationType = new LocationPageType();
+        $store->set($locationType->name, $locationType);
+    }
+}

src/Plugin.php

@@ -9,6 +9,7 @@
 use n5s\PageForCustomPostType\Core\RewriteManager;
 use n5s\PageForCustomPostType\Frontend\Handler;
 use n5s\PageForCustomPostType\Frontend\QueryFilter;
+use n5s\PageForCustomPostType\Integration\AdvancedCustomFields;
 use n5s\PageForCustomPostType\Integration\Autodescription;
 use n5s\PageForCustomPostType\Integration\IntegrationInterface;
 use n5s\PageForCustomPostType\Integration\Polylang;
@@ -184,6 +185,7 @@ public function onTemplateRedirect(): void
     public function getIntegrations(): array
     {
         return [
+            AdvancedCustomFields\AdvancedCustomFields::class,
             Polylang\Polylang::class,
             WordPressSeo\WordPressSeo::class,
             Wpml\Wpml::class,

tests/Integration/PluginTest.php

@@ -7,6 +7,7 @@
 use n5s\PageForCustomPostType\Container;
 use n5s\PageForCustomPostType\Core\Api;
 use n5s\PageForCustomPostType\Core\RewriteManager;
+use n5s\PageForCustomPostType\Integration\AdvancedCustomFields\AdvancedCustomFields;
 use n5s\PageForCustomPostType\Integration\IntegrationInterface;
 use n5s\PageForCustomPostType\Plugin;
 use n5s\PageForCustomPostType\Tests\Fixtures\TestCase;
@@ -62,6 +63,7 @@ public function testGetIntegrationsReturnsArrayOfIntegrationClassStrings(): void
 
         $this->assertIsArray($integrations);
         $this->assertNotEmpty($integrations);
+        $this->assertContains(AdvancedCustomFields::class, $integrations);
 
         foreach ($integrations as $integration) {
             $this->assertIsString($integration);

tests/Unit/ContainerTest.php

@@ -8,6 +8,7 @@
 use n5s\PageForCustomPostType\Container;
 use n5s\PageForCustomPostType\Core\Api;
 use n5s\PageForCustomPostType\Core\RewriteManager;
+use n5s\PageForCustomPostType\Integration\AdvancedCustomFields\AdvancedCustomFields;
 use n5s\PageForCustomPostType\Tests\Fixtures\TestCase;
 
 class ContainerTest extends TestCase
@@ -27,6 +28,13 @@ public function testGetReturnsCorrectTypeForApi(): void
         $this->assertInstanceOf(Api::class, $service);
     }
 
+    public function testGetReturnsCorrectTypeForAdvancedCustomFieldsIntegration(): void
+    {
+        $service = $this->container->get(AdvancedCustomFields::class);
+
+        $this->assertInstanceOf(AdvancedCustomFields::class, $service);
+    }
+
     public function testGetReturnsSameInstanceOnRepeatedCalls(): void
     {
         $first = $this->container->get(Api::class);
@@ -39,6 +47,7 @@ public function testHasReturnsTrueForKnownServices(): void
     {
         $this->assertTrue($this->container->has(Api::class));
         $this->assertTrue($this->container->has(RewriteManager::class));
+        $this->assertTrue($this->container->has(AdvancedCustomFields::class));
     }
 
     public function testHasReturnsFalseForUnknownServices(): void