requirements-amd.txt/requirements-nvidia.txt were pulling a multi-GB
torch wheel by default even though nothing in synapse/ imports torch,
transformers, accelerate, bitsandbytes, or PySide6 - dead weight that
made the pip batch fragile (one failed download could take unrelated
base deps down with it on a slow connection). Split the unused ML/GUI
stack out of requirements-base.txt into a new opt-in requirements-ml.txt,
and dropped the torch lines from the AMD/NVIDIA overlays and generator.
Also: recreate the venv if it exists but pip is missing, instead of
silently reusing a half-built one (ensurepip can fail during venv
creation and leave an interpreter with no pip).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
gen-nvidia-reqs.py wrote requirements-nvidia.txt with os.linesep, so running
it on Windows produced CRLF. Pinned to newline="\n".
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>