OCK Rotor Matrix media

Frozen prerelease captures:

  ock-readme-roundtrip.webm
  ock-readme-roundtrip.gif

These files are the current published Matrix demo assets.
Do not regenerate them implicitly when changing documentation.

Current manual / showcase Matrix profile:

  MATRIX_INPUT=README.md
  MATRIX_ROWS=22
  MATRIX_FOLLOW=6
  MATRIX_DELAY=0.03137

Run manually with:

  MATRIX_INPUT=README.md \
  MATRIX_ROWS=22 \
  MATRIX_FOLLOW=6 \
  MATRIX_DELAY=0.03137 \
  ./scripts/demo-matrix.sh

The slower 0.03137 profile is intended for human inspection/showcase.
The frozen WebM/GIF remain the prerelease media receipt.
