v0.1.4

Changed

• Transparency is traced natively, by default. An ink is a colour and an opacity and the
  transparent ground is an ink, instead of the image being composited onto white first:
  holes stay holes, white artwork on a transparent ground traces, translucent panels keep
  fill-opacity, and a glow or fade is one gradient of stop-color and stop-opacity.
  Opaque input traces byte-for-byte as before. --no-native-alpha (or
  INKVEC_NATIVE_ALPHA=0) restores the old path. Dark-ground pixel error on the screen set
  0.063 -> 0.0017.
• --cutout only matters with --no-native-alpha now.
• Shape harmonization is held to the traced boundary. A repeated shape takes the
  cluster's consensus geometry only where that stays within 0.1 px of where its own pixels
  put it and costs fewer parameters. A face that another face is drawn against — one punched
  out of the faces below it, or one with a translucent face in its hole — is never moved,
  so harmonizing can no longer open a gap onto a transparent ground; nor is a fitted circle
  or rounded rectangle. Screen set with the default flags: mean dE00 0.299 -> 0.148 (native
  transparency and this together), no icon above dE00 1.0, and the alpha-channel error of
  harmonized icons back to the unharmonized level (22 better, 0 worse).

Fixed

• Holes and outlines of fitted primitives. A hole written as two half-circle arcs had its
  ends and radius rounded separately and bulged by up to 0.76 px; a face with a hole drew its
  own outline from the traced ring rather than its primitive. A ring with one hole of uniform
  width is written as one stroked shape.
• The same input gives the same SVG on every machine. Without --time-budget, the
  boundary solve still stopped on a fixed 1200 ms wall clock (and the opt-in decode stage on
  600 ms), so a slower CPU, a loaded CI runner or WebAssembly could write different bytes for
  the same image. Only a caller's time budget runs a clock now; otherwise the solve stops on
  its iteration count. No output changes on the 246-icon screen set or on 1024 px rasters;
  two of eight complex 2048 px emoji change, for at most 1.4 s more time.
• Nested holes. A hole inside another hole of the same face is no longer written twice
  (even-odd filled it back in).
• White artwork on a transparent ground under --no-native-alpha no longer traces to a
  white rectangle.