Function format_duration 

pub fn format_duration(duration: Duration) -> String

Format duration in human-readable form

Converts duration to readable format (e.g., “1m 30s”).

Example

assert_eq!(format_duration(Duration::from_secs(0)), "0s");
assert_eq!(format_duration(Duration::from_secs(45)), "45s");
assert_eq!(format_duration(Duration::from_secs(90)), "1m 30s");
assert_eq!(format_duration(Duration::from_secs(3665)), "1h 1m 5s");