Gitea: TOTP TOCTOU race on web 2FA paths + missing replay check on Basic-Auth `X-Gitea-OTP` surface

Summary I'm reporting two related TOTP one-time-use defects in Gitea that survive the CVE-2021-45331 fix. The 2018 fix PR 3878 introduced the TwoFactor.LastUsedPasscode field and added an in-memory inequality check on the web 2FA login path. That check works correctly in the single-request case,...