The `--protected` flag on `dblab clone create` and `dblab clone update` currently accepts only plain minutes for custom durations (e.g. `--protected 120`). This is unintuitive for longer durations. Add support for human-readable duration suffixes: - `m` for minutes (e.g. `30m`) - `h` for hours (e.g. `2h` → 120 minutes) - `d` for days (e.g. `7d` → 10080 minutes) Plain numbers without a suffix remain interpreted as minutes for backward compatibility.