Implements SYNO.FileStation.Compress (v3) and SYNO.FileStation.Extract (v2)
with async polling identical to copy/move. Includes input validation for
compress (level, mode, format, empty paths) and 11 new unit tests.
Bumps version to 0.2.0.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>