Internal utility module for processing and expanding schema definitions.

This module handles the normalization and expansion of schema field definitions, converting shorthand syntax into fully expanded attribute lists. It processes nested schemas, array types, and evaluates function-based default values.

Key Functions

• expand/1 - Transforms a schema map by expanding each field definition
• Field normalization from shorthand to full attribute syntax
• Recursive processing of nested schemas and array types
• Default value evaluation for function-based defaults

This module is internal to Skema and not part of the public API.