Read text files with the encoding utf-8-sig so a BOM at the start of a
file does not cause a Unicode decode error (Windows editors add BOMs).
Reconstructed from ethie/pm commits 48a32b135b + 013219e814 onto the
current upstream/main base: only the utf-8 -> utf-8-sig transforms were
carried (370 exact line pairs across 205 files); pm-rename hunks that
rode in the original commit were left to the pm-store commit, and
utf8sig hunks entangled with content changes ride their owning commit.
Rebuilt on ethie/pm-clean off ac6c8028e0 (upstream/main).
Ships the hard A/B evaluation used for the August 2026 core-toolset
performance batch (#77056) as a reusable harness: 9 error-inducing trap
tasks derived from measured production waste classes, two-arm
PYTHONPATH-only comparison, ATOF-trace-based scoring, resume-safe
batteries.
Hardened from the original one-off: paths de-hardcoded (ABEVAL_ROOT /
ABEVAL_HOME), encoding= on all file IO, startup crashes retry on resume
instead of polluting cells, post-hoc grading fix for err_inline_script
baked in. Live-smoked end to end (baseline arm, qwen3-coder-30b,
err_multi_dir: exit 0, correct on-disk verification, resume record
written).
