test: preserve blocked macOS treated-media evidence

[miguel-heygen]

What

Test-only macOS arm64 real-pixel evidence gate for treated image/video capture. No HEVC or treatment product code is included.

Why

The treated-media issue was reported on macOS arm64 but did not reproduce on Linux or on the eligible hosted macOS arm64 runner. The coupled feature/fix plan required a valid platform product RED before any implementation.

How

• Generate sanitized raster image and video sources.
• Exercise ungraded, adjustment-only, and multipass treatment cases.
• Preserve runtime snapshot, raw pre-encode PNG, H.264, ProRes, and hvc1 HEVC boundaries with hashes, pixel statistics, alpha, and codec metadata.
• Count a product RED only when a graded boundary is uniform while its matching media-kind ungraded control is non-uniform.
• Reject filesystem root, home, repository root, artifact-space root, traversal, arbitrary external cleanup targets, and symlink escapes before recursive deletion.
• Terminate ffprobe options before the controlled input path.

Result

The hosted macOS 14.8.7 arm64 run classified no_reproduction: all six image/video cases were non-solid at every boundary, with no infrastructure failures and no product RED. The combined product task is blocked and paused.

Exact unblock condition: provide a reproducible eligible-environment artifact that produces a valid product RED under the control-aware predicate, or approve a new plan that explicitly removes the reproduction requirement. Until then, no HEVC or treatment implementation is authorized.

Test plan

• Unit tests added/updated

• Manual testing performed

• Documentation updated (not applicable to this blocked test-only draft)

• Harness safety tests: 4/4

• Producer ffprobe argv contract: 73/73

• Producer unit lane: 597/597 plus all Bun unit lanes

• Repository-contained real-pixel control: non-solid at runtime/raw/H.264/ProRes/HEVC

• macOS arm64 real-pixel matrix: no_reproduction, 30/30 boundaries non-solid