ENABLE_REGISTRATION default shift in Weblate 4.16 impacts open registration

Goal: Ensure that automated deployment scripts continue to create service accounts after upgrading to Weblate 4.16, where the default value of ENABLE_REGISTRATION changed from True to False.

Uncertainty remains about whether the environment variable WEBLATE_ENABLE_REGISTRATION=1 is reliably honored in containerized installations and what exact HTTP response the /accounts/register/ endpoint returns when the flag is left at its new default (e.g., a 403 Forbidden versus a redirect) across different debug/production modes.

• Does setting WEBLATE_ENABLE_REGISTRATION=1 in the container environment reliably enable registration in Weblate 4.16?
• When ENABLE_REGISTRATION is unspecified, what is the precise HTTP status code and response body returned by /accounts/register/ in production versus debug mode?
• Are there any side‑effects on existing authentication backends or already‑registered users when toggling ENABLE_REGISTRATION after an upgrade?