DID-scoped Ed25519 auth implemented: Opake-Ed25519 header scheme with timestamp replay protection, DID scope enforcement, key caching with 5-min TTL, bearer token fallback. Health endpoint is unauthenticated. Auth middleware uses from_fn_with_state for AppState access.
DID-scoped Ed25519 auth implemented: Opake-Ed25519 header scheme with timestamp replay protection, DID scope enforcement, key caching with 5-min TTL, bearer token fallback. Health endpoint is unauthenticated. Auth middleware uses from_fn_with_state for AppState access.