Python jobs under nsjail experience slow imports (~465ms for `import
requests`) because dependency directories are mounted read-only. Without
pre-compiled `.pyc` files, Python recompiles `.py` source to bytecode
in-memory on every import in every fresh nsjail process, paying the cost
repeatedly.
Add `--compile-bytecode` to both `uv pip install` invocations (the
Rust-driven install in python_executor.rs and the nsjail
download_deps.py.sh script) so `.pyc` files are generated at install
time and available at runtime even through read-only mounts. The files
are included in both the local cache and S3 piptar uploads.
The flag is supported by the uv version (0.9.24+) shipped in the
Dockerfile. The existing `__pycache__` skip only filters top-level dirs
for dedup logic, not subdirs within packages, so there is no conflict.
Fixes WIN-2001
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>