1.0.0-alpha.4

Changed

• --watershed-detail (and watershed_detail on Config and in the Python and Node bindings) is no longer capped at 255 — it now accepts any value, so extremely fine segmentation is reachable past the old ceiling. The default stays 128 and each +25.5 still roughly doubles the region count.
• Bump visioncortex to 0.9.3 — a minor upstream bug fix.