Authorization endpoint for the OAuth 2.0 Authorization Code flow. The client redirects the user's browser here; the authorization server prompts for consent and then redirects back to redirect_uri with an authorization code, which the client exchanges for an access token at /oauth2/token.

This endpoint does not require the X-Vibe-Revision header.

The X-Vibe-Revision header and the standard Vibe API security schemes do not apply here — authentication is performed by the authorization server itself against the client registration.