Fix: pip hangs in WSL (IPv6 / gai.conf)

Pain Point pip install hangs in WSL with no useful error, often after it starts fetching from files.pythonhosted.org . The Rule If DNS/connection to files.pythonhosted.org hangs but pypi.org works, suspect IPv6 preference + broken IPv6 routing. Minimal Diagnosis python -c "import urllib.request; print(urllib.request.urlopen('https://pypi.org/simple/').status)" # expected: 200 getent hosts pypi.org…