Our `devtest` page contains some good UI examples which should be taken
as example when working on Gitea UI. Mention it in our frontend
contributing guidelines to for new contributors to know about it.
The PKCE flow according to [RFC
7636](https://datatracker.ietf.org/doc/html/rfc7636) allows for secure
authorization without the requirement to provide a client secret for the
OAuth app.
It is implemented in Gitea since #5378 (v1.8.0), however without being
able to omit client secret.
Since #21316 Gitea supports setting client type at OAuth app
registration.
As public clients are already forced to use PKCE since #21316, in this
PR the client secret check is being skipped if a public client is
detected. As Gitea seems to implement PKCE authorization correctly
according to the spec, this would allow for PKCE flow without providing
a client secret.
Also add some docs for it, please check language as I'm not a native
English speaker.
Closes#17107Closes#25047
Denys Konovalov