• Lunar version: 1.0.0-beta.6
• Laravel Version: 11.35.1
• PHP Version: 8.3.15
• Database Driver & Version: MySQL 8

Expected Behaviour:

When creating a custom attribute file field type by following the documentation, the file should be correctly saved, and its reference should be stored in the database.

Actual Behaviour:

When attempting to save a custom attribute file field type, an error occurs. The issue seems to stem from the AttributeData class, specifically in the ->mutateDehydratedStateUsing method. There is an if condition that checks:
if ($attribute->type == FileFieldType::class)
Since a custom attribute file field type is not strictly equal to FileFieldType::class, this condition does not execute.

Steps To Reproduce:

1. Follow the Lunar documentation to create a custom attribute field type for a file upload.
2. Attempt to save a record with this custom file field type.
3. Observe that an error occurs because the if condition does not account for custom file field types.