Mixin for configuring PaperTrail version tracking on Layout resources.

This mixin provides the database and action configuration needed for the PaperTrail extension to track layout versions. It defines the version table structure, database relationships, and actions required for version management, ensuring consistent configuration across the layout versioning system.

The mixin sets up the 'layout_versions' table with proper foreign key references that cascade delete when the source layout is removed. It also defines a bypass action for retrieving versions without tenant restrictions, enabling cross-site version access for administrative purposes.

By using a mixin approach, the versioning configuration is kept separate from the main Layout resource definition, improving maintainability and allowing the versioning setup to be reused or modified independently. The configuration ensures that layout history is properly tracked while maintaining referential integrity.