Bug: data-color-grading renders solid white (mp4) or black (prores) frames — both 0.7.109 and 0.8.2

Environment

• hyperframes CLI 0.7.109 and 0.8.2 (both tested, identical behavior)
• macOS arm64 (Darwin 25.4.0)
• Static <img> with data-color-grading applied via hyperframes media-treatment --apply

Reproduction

1. Create a composition with a full-frame <img> (with id for strict lint):

<img id="media-frame" class="clip" src="frame.png" data-start="0" data-duration="1" data-track-index="1" style="left:50%;top:50%;width:1920px;height:1080px;object-fit:cover;">

2. Apply a grading patch:

hyperframes media-treatment --project . --file index.html --selector "img#media-frame" --grading '{"effects":{"kuwahara":0.8}}' --apply

3. Render:

hyperframes render . --format mp4 --output out.mp4 --fps 30 --quiet --strict-all

Results (4-condition matrix)

Expected

The graded image should render with the color treatment applied, not a solid color frame.

Key observations

• Any data-color-grading attribute (regardless of effect type: effects.* or adjust.*) triggers the bug
• Removing the data-color-grading attribute restores normal rendering
• Bug is identical across 0.7.109 and 0.8.2
• The CLI --apply succeeds (ok: true) and writes a complete ~80-key data-color-grading JSON to the element
• The composition HTML skeleton uses #stage with data-composition-id, data-no-timeline, data-start/duration/width/height/fps — worker-standard structure

Reproduction package

A tarball with the minimal project (HTML + frame + 4 rendered outputs) is available. The command sequence above reproduces it from scratch.

Impact

This blocks the "deterministic media treatment" pipeline for any project that renders graded media through the standard composition path.