Make site section vocabulary configurable and simplify settings form

Add a vocabulary selector to the settings form so the site section
vocabulary is no longer hardcoded. Remove node bundle checkboxes
(section_page/content_page are always included), keep user and group
as configurable parent targets. All hardcoded 'site_sections'
references in PHP replaced with dynamic config reads via helper.

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

structural_pages.install

@@ -13,7 +13,7 @@ use Drupal\taxonomy\Entity\Term;
  * Implements hook_install().
  */
 function structural_pages_install(): void {
-  // Create default terms for site_sections vocabulary.
+  // Create default terms for the configured vocabulary.
   _structural_pages_create_default_terms();
 
   // Display success message.
@@ -21,10 +21,10 @@ function structural_pages_install(): void {
 }
 
 /**
- * Creates default terms for the site_sections vocabulary.
+ * Creates default terms for the configured site section vocabulary.
  */
 function _structural_pages_create_default_terms(): void {
-  $vocabulary = 'site_sections';
+  $vocabulary = _structural_pages_get_vocabulary();
 
   // Check if terms already exist (avoid duplication on reinstall).
   $existing = \Drupal::entityQuery('taxonomy_term')
@@ -210,10 +210,11 @@ function structural_pages_uninstall(): void {
     }
   }
 
-  // Remove terms from site_sections vocabulary.
+  // Remove terms from the configured vocabulary.
+  $vocabulary = _structural_pages_get_vocabulary();
   $tids = \Drupal::entityQuery('taxonomy_term')
     ->accessCheck(FALSE)
-    ->condition('vid', 'site_sections')
+    ->condition('vid', $vocabulary)
     ->execute();
   if ($tids) {
     $terms = $entity_type_manager->getStorage('taxonomy_term')->loadMultiple($tids);
@@ -227,7 +228,7 @@ function structural_pages_uninstall(): void {
     // Pathauto patterns.
     'pathauto.pattern.section_page',
     'pathauto.pattern.content_page',
-    'pathauto.pattern.site_sections_term',
+    'pathauto.pattern.' . $vocabulary . '_term',
     // Entity displays.
     'core.entity_form_display.node.section_page.default',
     'core.entity_view_display.node.section_page.default',
@@ -246,7 +247,7 @@ function structural_pages_uninstall(): void {
     'node.type.section_page',
     'node.type.content_page',
     // Vocabulary.
-    'taxonomy.vocabulary.site_sections',
+    'taxonomy.vocabulary.' . $vocabulary,
   ];
 
   $config_factory = \Drupal::configFactory();
@@ -290,15 +291,16 @@ function structural_pages_update_10003(): void {
 }
 
 /**
- * Fix content translation config and update site_sections term translations.
+ * Fix content translation config and update term translations.
  */
 function structural_pages_update_10004(): void {
   // Ensure content translation is properly configured for the vocabulary.
   _structural_pages_ensure_content_translation();
 
+  $vocabulary = _structural_pages_get_vocabulary();
   $terms = \Drupal::entityTypeManager()
     ->getStorage('taxonomy_term')
-    ->loadByProperties(['vid' => 'site_sections']);
+    ->loadByProperties(['vid' => $vocabulary]);
 
   if ($terms) {
     _structural_pages_add_term_translations($terms);
@@ -306,14 +308,15 @@ function structural_pages_update_10004(): void {
 }
 
 /**
- * Ensures content translation settings exist for site_sections vocabulary.
+ * Ensures content translation settings exist for the configured vocabulary.
  */
 function _structural_pages_ensure_content_translation(): void {
   if (!\Drupal::moduleHandler()->moduleExists('content_translation')) {
     return;
   }
 
-  $config = \Drupal\language\Entity\ContentLanguageSettings::loadByEntityTypeBundle('taxonomy_term', 'site_sections');
+  $vocabulary = _structural_pages_get_vocabulary();
+  $config = \Drupal\language\Entity\ContentLanguageSettings::loadByEntityTypeBundle('taxonomy_term', $vocabulary);
   $config->setDefaultLangcode('site_default');
   $config->setLanguageAlterable(TRUE);
   $config->setThirdPartySetting('content_translation', 'enabled', TRUE);
@@ -327,19 +330,20 @@ function structural_pages_requirements(string $phase): array {
   $requirements = [];
 
   if ($phase === 'runtime') {
-    // Check if site_sections vocabulary has terms.
+    // Check if the configured vocabulary has terms.
+    $vocabulary = _structural_pages_get_vocabulary();
     $term_count = \Drupal::entityQuery('taxonomy_term')
       ->accessCheck(FALSE)
-      ->condition('vid', 'site_sections')
+      ->condition('vid', $vocabulary)
       ->count()
       ->execute();
 
     if ($term_count === 0) {
       $requirements['structural_pages_terms'] = [
         'title' => t('Structural Pages'),
-        'value' => t('No terms in site_sections vocabulary'),
-        'description' => t('The Structural Pages module requires terms in the "Site Sections" vocabulary. <a href=":url">Add terms</a>.', [
-          ':url' => '/admin/structure/taxonomy/manage/site_sections/add',
+        'value' => t('No terms in @vocabulary vocabulary', ['@vocabulary' => $vocabulary]),
+        'description' => t('The Structural Pages module requires terms in the site section vocabulary. <a href=":url">Add terms</a>.', [
+          ':url' => '/admin/structure/taxonomy/manage/' . $vocabulary . '/add',
         ]),
         'severity' => REQUIREMENT_WARNING,
       ];