Add --use-uv flag for faster venv creation using uv

[budaesandrei]

Summary

Adds an opt-in --use-uv flag to create_venvs.py that uses uv instead of the stdlib venv + pip for significantly faster virtual environment creation and package installation.

Changes

• Added is_uv_available() helper to check if uv is on PATH.
• Added uv_install() function that uses uv pip install --python <venv_python> for package installation.
• Updated create_venv() to accept a use_uv parameter:
  • When True: uses uv venv for venv creation and uv pip install for all packages, skipping the pip upgrade step (not needed with uv).
  • When False (default): behavior is completely unchanged.
• Added --use-uv argparse flag with a clear error message if uv is not installed.
• Updated README with usage example.

Compatibility

• CI workflows are unaffected — they call create_venvs.py --target production without --use-uv.
• uv venv produces a standard venv structure (bin/activate, bin/python) so all downstream consumers (quality checks, linting, unit tests, build scripts, VS Code settings) work identically.
• Requirements files use standard PEP 508 syntax fully supported by uv.
• The flag is purely opt-in — no existing behavior changes without it.

Testing

Verified the following scenarios:

• --use-uv with uv installed — creates venv with uv venv, installs packages with uv pip install
• Without --use-uv — identical behavior to before
• --use-uv without uv installed — exits with clear error message
• --use-uv with --recreate — properly deletes and recreates venv using uv
• --help — new flag appears in usage output

[Mercury2699]

Thank you for your contribution!

Overall this is solid work — the approach is clean and well-scoped.

The PR also has a merge conflict with main that will need a rebase before this can land.

Happy to approve once the comments and the rebase are addressed.

[Mercury2699]

nit: Without --python, uv picks its own default interpreter, which, although unlikely, may not match what verify_python_version() validated above — silently creating a venv on a different Python version.

Suggested fix:

subprocess.run(["uv", "venv", "--python", sys.executable, str(venv_path)], check=True)

[Mercury2699]

The existing codebase already has Windows support — the README documents a PowerShell 5.1 setup, and main already guards against Windows in create_venv():

# Already in main branch:
venv.create(venv_path, with_pip=True, symlinks=(sys.platform != "win32"))

So Windows developers do run create_venvs.py locally. This hardcoded path will silently fail for them — Windows venvs use Scripts\python.exe, not bin/python.

Suggested fix:

python_path = str(Path(venv_dir) / ("Scripts" if sys.platform == "win32" else "bin") / "python")