v1.0.0

• Initial release: type-safe, immutable, non-negative duration value object (Stringable).
• Stored internally as microseconds; factories zero/micros/millis/seconds/minutes/hours/days.
• Conversions: toMicros (exact), toMillis (rounded up via ceil), toSeconds (float), toMinutes (float).
• Saturating arithmetic plus/minus; static binary min/max.
• Comparisons compareTo/equals/isGreaterThan/isLessThan/isZero/isPositive.
• __toString() with fixed human-readable format (µs/ms/s/min/h/d, largest fitting unit).
• Property-based tests for algebraic laws (commutativity, associativity, antisymmetry, round-trip, absorption).