Function validate_hhmm_range 

pub fn validate_hhmm_range(
    dtm_value: &str,
    min: &str,
    max: &str,
) -> ConditionResult

Validate that a DTM value’s HHMM portion is within a range (inclusive).

Example: validate_hhmm_range("202601011530+00", "0000", "2359") → True