import pkg.sub.mod does not run pkg/init.py

Found 2026-10-20 while testing __name__. With pkg/__init__.py printing a line, CPython prints it before pkg/sub/mod.py's output; pxx skips it. Seen on HEAD before the __name__ change too. Anything a package's __init__ sets up (module-level state, re-exports with side effects) is missing.