oauth2-redirect-verifier value

## 💬 Question here

I am a bit concerned about potential security issues and so I am wondering if the "oauth2-code-verifier" is the hashed version (code challenge) of the plain text Code Verifier?

It it IS hashed, I guess there is no security issue...?
If it is NOT hashed, then it seems like it does not fulfill Oauth2 protocol...? (Im not claiming necessarily, Im asking)
Ref.:
https://datatracker.ietf.org/doc/html/draft-ietf-oauth-security-topics#name-authorization-code-grant


## Your Environment

- *node version*: 22
- *fastify version*: 7.8.0
- *os*: Linux (docker container running on Mac)