workflow_steps replaced PATH with the interpreter dir plus os.defpath. A
Windows venv ships only python.exe and os.defpath carries no Git usr/bin,
so replaying the ubuntu `gate-lanes` step (`python3 - <<PY`) died with
`python3: command not found` and the selection steps lost sort/tr/paste/find;
on Linux a missing python3 silently fell through to the host interpreter.
The replay now resolves bash via hermes_platform.resolver, adds that bash's
dir (Git usr/bin on Windows, already on defpath on Linux) after os.defpath,
and drops a disposable python/python3 shim to REPLAY_PYTHON only for a name
the interpreter dir lacks, mirroring setup-python putting both on PATH.
Production YAML is unchanged; on a Linux venv no shim is written.
855a4b21aa