Forgot Password answers every address the same way and emails a code only
to an active account. Codes are stored as salted SHA-256 hashes, expire 15
minutes after issue, are replaced by a newer request, and are checked only
against the email they were issued to. Five failed checks delete the code;
attempts are reserved with one conditional UPDATE so concurrent guesses
cannot exceed the budget. VerificationCode requires the email, and email and
code are accepted in the JSON body so they stay out of URLs.
The three anonymous endpoints are rate limited to 10 requests per 15
minutes per client IP. Forwarded headers are trusted only through loopback
and private hops, since the API sits behind the EB load balancer and nginx.
The migration adds hash, salt, expiry and attempt columns and deletes the
old plaintext rows.
