OS Birthdate Field Normalizes Age Checks

systemd merged an optional, administrator‑set birthDate field into its userdb JSON record so downstream desktop and system components can build age‑verification flows for laws in California, Colorado and Brazil. The field is optional and systemd's maintainer says it enforces no policy, but it creates a standardized place in the OS stack where age metadata can live. — Standardizing where birthdates are stored in core OS components shifts compliance infrastructure into the operating system, raising questions about data governance, consent, centralization, and surveillance risk.