fmtDurDays function
Formats Duration as "Xd Yh" when 24 hours or longer (e.g. "3d 4h"), or delegates to fmtDurLong when under 24 hours (FEAT-130).
Implementation
String fmtDurDays(Duration d) {
if (d.inDays > 0) {
final days = d.inDays;
final hours = d.inHours.remainder(24);
return '${days}d ${hours}h';
}
return fmtDurLong(d);
}