Lets users regenerate a personal access token's value in place, keeping
its name and scopes, instead of deleting and recreating it. Useful when
a token was shared with a third party (e.g. an AI agent) and needs to
be invalidated immediately without redoing scope selection.
Follows the same pattern already used for OAuth2 application client
secrets (`GenerateClientSecret`/`RegenerateSecret`).
**Testing**: added a model unit test and a web integration test;
manually
verified in the running dev server that the old token stops
authenticating
and the new one works immediately after regenerating.
<img width="1040" height="245" alt="image"
src="https://github.com/user-attachments/assets/4de0d8b4-1fc4-49cf-a859-95e24d0b2c0a"
/>
Fixes#38683.
---------
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Closes#27455
> The mechanism responsible for long-term authentication (the 'remember
me' cookie) uses a weak construction technique. It will hash the user's
hashed password and the rands value; it will then call the secure cookie
code, which will encrypt the user's name with the computed hash. If one
were able to dump the database, they could extract those two values to
rebuild that cookie and impersonate a user. That vulnerability exists
from the date the dump was obtained until a user changed their password.
>
> To fix this security issue, the cookie could be created and verified
using a different technique such as the one explained at
https://paragonie.com/blog/2015/04/secure-authentication-php-with-long-term-persistence#secure-remember-me-cookies.
The PR removes the now obsolete setting `COOKIE_USERNAME`.
Mitrahsoft