Update PDS to v0.4.208 and fix OAuth ingress routing
Upgrade PDS from pinned pre-OAuth digest to 0.4.208, which serves
.well-known/oauth-authorization-server and /oauth/* endpoints.
Simplify ingress to catch-all for sans-self.org instead of
allowlisting individual path prefixes, preventing future breakage
as the PDS adds new endpoints. Admin routes remain blocked.