fix: add comments

Author: iamquang95

crates/dkg/src/sync/handler.rs

@@ -424,6 +424,8 @@ async fn handle_inbound_stream(
                 }
             }
 
+            // Record observed step even after validation failure.
+            // Barrier waiters still fail fast on `server.err`
             if server.update_step(peer_id, message.step).await? {
                 send_inbound_event(
                     &inbound_events_tx,

crates/dkg/src/sync/protocol.rs

@@ -1,6 +1,7 @@
 //! Protocol helpers for the DKG sync protocol.
 
 use libp2p::identity::{Keypair, PublicKey};
+use libp2p::StreamProtocol;
 use pluto_core::version::SemVer;
 
 use crate::dkgpb::v1::sync::MsgSync;
@@ -10,8 +11,6 @@ use super::error::{Error, Result};
 /// The protocol identifier for DKG sync.
 pub const PROTOCOL_NAME: libp2p::StreamProtocol = StreamProtocol::new("/charon/dkg/sync/1.0.0/");
 
-use libp2p::StreamProtocol;
-
 /// Signs the definition hash using the same libp2p signing path as Go.
 pub fn sign_definition_hash(secret: &k256::SecretKey, def_hash: &[u8]) -> Result<Vec<u8>> {
     let mut der = secret