Function validate 

pub fn validate(value: &Value, schema: &Value) -> Result<()>

Validate a JSON value against a JSON Schema

This is a basic validator that checks common schema constraints:

• Type checking (string, number, integer, boolean, array, object)
• Required properties
• Enum values
• Array items

Note: This is not a complete JSON Schema validator. For production use, consider using a dedicated JSON Schema validation library.