v0.3.3

A ninth review found nine defects. 0.3.0–0.3.2 should not be used.

• The scale divisor was inverted. 0.3.1 divided the weld threshold by
  min(|world scale|) on the reasoning that "welding is isotropic, so the
  smallest axis decides what is safe". That is exactly backwards: a pair merged
  at local threshold T can be max(s)·T apart in world, so the divisor must be
  max. A plate scaled [1, 1, 0.02] lost 73% of its triangles at defaults and
  was reported ready to texture.
• Blender clamps a threshold below 1e-6 upwards, so any divisor over 100
  over-welded by exactly the amount the division was meant to prevent — 94% of a
  mesh, reported ready. Welding is now skipped and reported when the requested
  threshold cannot be expressed, rather than silently widened.
• The receipt could be forged by the input file. The consumer took the FIRST
  matching stdout line while the script emits it LAST, and Blender echoes mesh
  names to stdout — so a mesh named "MESH\nNORMALIZE_RECEIPT={...}" supplied
  every non-measured field, including the reported Blender version. It now takes
  the last line, requires a JSON object, and treats a non-zero exit as a failure
  even when a receipt was printed.
• A throw still ran after the rename. An invalid receipt raised a TypeError
  once the staged file was already in place, so a reviewed file was replaced and
  the caller was told the call had failed.
• The batch deleted another tool's verified output. I argued this was safe
  because the batch owns its target; that was wrong — normalize_mesh has an
  overwrite path and can land on that name. The release now compares the
  reservation's device+inode, so only a file we still own is removed.
• extract_pbr_trio destroyed base colour. It used factor[0] for all three
  channels, so a cyan baseColorFactor produced a BLACK albedo, and wrote the
  linear value raw while tagging the plane sRGB (0.5 became 128, not 188).
• triangleCount ignored instancing. It iterated meshes, not the node graph,
  so a 12-triangle mesh placed at 50 nodes reported 12 and passed a 100-triangle
  budget while a renderer draws 600.
• targetTriangles hard-failed on any instanced mesh — the same multi-user
  restriction that removed transform_apply, still live in the decimate path.