First real execution of soak-conpty.ps1 on GitHub's windows-latest proved the
harness works — it spawned real ConPTY children, ran the suite (6 tests), and
measured the first iteration — then died printing the per-iter line: `{3,+4}`
is a printf-ism, not valid .NET composite formatting (the `+` is rejected with
"Expected an ASCII digit"). The script had never run on Windows before, so the
typo was latent. Drop to `{3,4}` (plain width).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
jpmschweitzerandClaude Opus 4.8
c1d14bbaf0