GHSA-387m-j3p9-3php

### Summary The password forgot endpoint returned different responses for registered and unregistered emails, allowing user enumeration.

### Details `POST /api/v2/auth/password/forgot` returned a success message for registered emails but `'Your email has not been registered.'` for unknown emails. The fix returns a uniform response regardless of whether the email exists.

### Impact An unauthenticated attacker can determine whether an email is registered. No credentials or data are exposed.

### Credit This issue was reported by [@Tulgaaaaaaaa](https://github.com/Tulgaaaaaaaa).