v0.3.2

Fix

• Duration::to_string_repr Int64::min_value overflow — negating `Int64::min_value` wraps back to itself, producing garbled output with negative sub-components. Restructured to divide-first on the signed nanosecond value then abs each bounded component individually. Safe across the full `Int64` range with no new abort paths.

Also

• Added a doc note on `DateTime::format` clarifying that expanded-year output (years outside 0000–9999) cannot be round-tripped through `DateTime::parse`, which accepts only 4-digit positive years per RFC 3339.