Scope

Enable the OAuth 2.0 client credentials grant in django-oauth-toolkit. This is a general M2M capability, not SCIM-specific — any machine client (CI/CD, internal tooling, IdP SCIM clients) benefits from short-lived tokens over static API keys.

• Enable client-credentials grant type in OAUTH2_PROVIDER settings.
• Add client_credentials to grant_types_supported in the authorization server metadata endpoint.
• Allow creating OAuth Applications with the client-credentials grant type (via Django admin or API).
• Define a scim scope in OAUTH2_PROVIDER["SCOPES"].

Acceptance criteria

• An OAuth Application with client-credentials grant type can be created.
• A POST to /o/token/ with grant_type=client_credentials, valid client_id/client_secret, and scope=scim returns a short-lived access token.
• The authorization server metadata endpoint lists client_credentials in grant_types_supported.
• Existing OAuth flows (Authorization Code + PKCE) are unaffected.