Allow admin to set theme for new and existing users with API

[tobiasbp]

Feature Description

It would be nice if the following endpoints could be updated to include field theme, which would allow an administrator to configure the theme for new and existing users on a Gitea instance:

• PATCH: /admin/users/<user>
• POST: /admin/users
• GET: /admin/users

Use case: If a theme selected by a user no longer exists, there is no way to set the user's theme to a currently available theme.

Screenshots

No response

[silverwind]

Use case: If a theme selected by a user no longer exists, there is no way to set the user's theme to a currently available theme.

Sidenote: What happens when a theme is deleted that is in use? Do the users get the "no theme" black on white view? I think we could in such cases automatically fall back to the default theme ("gitea-auto").

[wxiaoguang]

I think we could in such cases automatically fall back to the default theme ("gitea-auto").

It has been implemented in 1.22 by #30625

https://github.com/go-gitea/gitea/pull/30625/files#diff-df6792f0bd4f2d349508731c08110a47e5cf0c9559f863f9bb5d7c37cd4f1240R261-R269

[wxiaoguang]

Use case: If a theme selected by a user no longer exists, there is no way to set the user's theme to a currently available theme.

@tobiasbp is it still a problem in 1.22? I think 1.22 could fall back to the default theme in this case.

[GiteaBot]

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