Mirrors test_compare_test_results.py: covers human_kb formatting,
load_sizes (date-keyed and flat), compare() including threshold
boundaries on both growth and shrinkage, format_report, and an
end-to-end main() check that the comment file is only written when
something significant is reported.
Wired into code-quality.yml alongside the existing compare_test_results
unit tests.
New workflow mirroring GnuComment.yml: triggers on workflow_run of
make, downloads the size-comment artifact for the corresponding PR,
and posts the per-binary size comparison as a PR comment when there
is something significant to report.
Replace the inline shell loop that walked individual-size-result.json
with a call to util/compare_size_results.py and write its output, plus
the PR number, into a size-comment/ directory uploaded as an artifact.
The aggregate `multiple binaries` and `multicall binary` checks remain
inline since they are simple scalar comparisons. The new artifact is
consumed by the SizeComment workflow to post a PR comment, mirroring
the GnuTests / GnuComment pipeline.