Function handle_rename 

pub fn handle_rename(args: &RenameArgs) -> Result<()>

Handle rename command to rename environment variables using patterns.

Errors

This function will return an error if:

• Environment variable operations fail (loading, renaming)
• Pattern matching fails or produces invalid results
• Variable names conflict or are invalid
• File I/O operations fail when persisting changes
• User input cannot be read from stdin during confirmation