- Replace module-level globals with _mp_state dict (PLW0603)
- Use hashlib.sha256 instead of md5 (S324)
- Use secrets.randbelow instead of random.randrange (S311)
- Use tempfile.gettempdir() instead of hardcoded /tmp (S108)
- Replace assert statements with RuntimeError (S101)
Move warsaw_bridges, warsaw_districts, warsaw_landmarks, warsaw_metro,
warsaw_osiedla, warsaw_streets, and car_brand_logos into the existing
python_pkg/anki_decks/ directory alongside the polish_* generators.
Also move preview_all.html into anki_decks/.
Update all import paths, filesystem references in geo_data.py,
docstrings, READMEs, test imports, and .gitignore accordingly.
