Improve OAuth metadata

• https://bsky.app/profile/dame.is/post/3lxdfrg574k2e

Changing the metadata filepath to /oauth-client-metadata.json to display only the app domain helps with the OAuth Authorization page and in the Account page (where users can manage OAuth access, it's '{PDS URL}/account' or 'bsky.social/account').

Rocksky currently shows up like this .

It's possible to adjust the name and name too. A thread for reference that could help figure it out, since there is no clear documentation:

• https://bsky.app/profile/tijs.org/post/3m5qt5izhw22k