Sol controls posters (modified files)

so-101-poster.webp, lekiwi-poster.webp and open-duck-mini-v2-poster.webp are
not upstream bytes. Infinomni made them for the Sol controls pitch from the
SO-101, LeKiwi and Open Duck Mini v2 images in /open-robots/remix-previews/
(so-101.webp, lekiwi.jpg and open-duck-mini-v2.png). Each is cropped to 4:3,
resized to 400x300 pixels and re-encoded as WebP.

Those images' attributions (/open-robots/remix-previews/NOTICE.txt) and the
Apache-2.0 license apply to these posters. A copy of the license is in this
directory: LICENSE-Apache-2.0.txt.

posters.json records each poster's source file (derivedFrom.file names a file
in /open-robots/remix-previews/) and its hash, the change made, and the
poster's own hash.

The posters live here, outside /open-robots/, because the robot worker's image
copies /open-robots/ and nothing it runs reads them
(infra/robot-platform-worker.lock.json).