Require email at registration (editable on profile), add a Resend mailer with idempotent first-answer sends, and keep answer saves independent of delivery.
Replace username-based admin bootstrap with a one-time setup secret, rate-limit login/register, equalize login bcrypt timing, cap passwords at 72 bytes, destroy sessions on logout, and require Secure cookies when PORT is set.
Introduce a Store interface with Postgres and in-memory backends, cover mutations/CSRF/session rotation without Postgres, bound avatar decode dimensions, add truncate/prepareAvatar unit tests, and run go test -race in CI.
codegirl007