- Added MediaAssetVariant enum with values 'main' and 'preview'.
- Updated media asset service logic to utilize MediaAssetVariant for variant handling.
- Refactored database models and queries to include variant and source_asset_id fields.
- Enhanced validation for asset variants in upload and processing functions.
- Updated Swagger documentation to reflect new variant structure and descriptions.
- Implemented necessary database migrations to support the new variant constraints.
- Add TenantOptionalAuth middleware to allow access to public content without requiring authentication.
- Introduce ListPublicPublished and PublicDetail methods in the content service to retrieve publicly accessible content.
- Create tenant_public HTTP routes for listing and showing public content, including preview and main asset retrieval.
- Enhance content tests to cover scenarios for public content access and permissions.
- Update specifications to reflect the new public content access features and rules.
