Container names, FastAPI titles, email subjects, filenames, brand text,
session cookie, User-Agent, docstrings, README. Volume lazyflat_data and
/data/lazyflat.sqlite already used the new name, so on-disk data is
preserved; dropped the now-obsolete legacy-rename comments.
Side effect: SESSION_COOKIE_NAME change logs everyone out on deploy.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>