section 9 now carries a concrete instance of its own argument: a test found a bug that
two careful readings of the file had not, in code written three days earlier to prevent
exactly that failure. also records the two bun/testing-library harness facts that cost
more than the fix did, since both present as an unrelated file breaking for no reason.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>