compare-web-captures and compare-web-screenshots parsed their arguments as
inline JSON only, unlike every other JSON-input command. Screenshot
artifacts and scenario captures embed base64 PNG bytes, so a typical
viewport screenshot exceeds the command-line length limit (128 KiB per
argument on Linux, 1 MiB total on macOS) and could not be compared from
the CLI at all, while MCP accepts it. A file path was reported as
malformed JSON, and screenshot schema failures returned no issues.
Each argument now accepts inline JSON or a JSON file path through
parseCliJsonInput; file failures keep its path diagnostics, malformed
inline JSON keeps the field issue, and screenshot validation reports
projected schema issues. The tests share one CLI JSON process fixture.
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Kaoru0822