a3d 0.9.3

[0.9.3] - 2026-09-14

Packaging only. Nothing in src/ moved, and a build that worked on 0.9.2
builds identically here.

The first upload to the ESP Component Registry carried 4.1 MB, of which 5.8 MB
uncompressed was pictures and Arduino model headers: idf.py add-dependency
put the banner, the showcase GIF and two model-as-header arrays into every
consumer's managed_components/, and no ESP-IDF build reads any of them.

Changed

• The README's two images are referenced by absolute
  raw.githubusercontent.com URL rather than by relative path, so they render
  on the registry and on PlatformIO without the files being shipped.
• idf_component.yml excludes a3d_banner.jpeg, a3d_showcase.gif and
  examples/Arduino/**; library.json excludes the two images. The registry
  archive drops from 4.1 MB to 0.5 MB. Arduino and PlatformIO still get
  the Arduino examples - only the ESP-IDF package leaves them out.
• The README's ESP-IDF install section leads with
  idf.py add-dependency "0015/a3d^0.9.3" now that the component is on the
  registry, and keeps the git dependency as the way to get the tree the
  registry copy trims. a3d_export.py --project pins v0.9.3.