Derive Macro ProtoMessage 

#[derive(ProtoMessage)]
{
    // Attributes available to this derive:
    #[proto]
}

Derives the owned asupersync::grpc::protobuf::ProtoMessage contract.

Fields use #[proto(kind, tag = N)], with explicit optional, repeated, and packed modifiers. Maps use #[proto(map, key = "string", value = "uint64", tag = N)]; oneofs use an Option<T> field annotated with #[proto(oneof, tags = "N, M")].

Expansion is deterministic and Cargo-only: it invokes no schema compiler and reads no ambient files.