Initial commit: Site Structure module for Drupal

Drupal module that provides hierarchical site structure management
with support for sections, categories, and content items. Includes
path aliases with tokens, breadcrumb integration, and admin interface.

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

config/install/field.field.node.content_page.field_parent_page.yml

@@ -0,0 +1,44 @@
+langcode: en
+status: true
+dependencies:
+  config:
+    - field.storage.node.field_parent_page
+    - node.type.content_page
+    - node.type.section_page
+    - taxonomy.vocabulary.site_section
+  module:
+    - dynamic_entity_reference
+id: node.content_page.field_parent_page
+field_name: field_parent_page
+entity_type: node
+bundle: content_page
+label: 'Parent Page'
+description: 'Select the parent entity. The site section will be inherited automatically based on the parent type.'
+required: false
+translatable: false
+default_value: {  }
+default_value_callback: ''
+settings:
+  entity_type_ids:
+    - node
+    - taxonomy_term
+  node:
+    handler: 'default:node'
+    handler_settings:
+      target_bundles:
+        content_page: content_page
+        section_page: section_page
+      sort:
+        field: title
+        direction: asc
+      auto_create: false
+  taxonomy_term:
+    handler: 'default:taxonomy_term'
+    handler_settings:
+      target_bundles:
+        site_section: site_section
+      sort:
+        field: name
+        direction: asc
+      auto_create: false
+field_type: dynamic_entity_reference