chore: refactor module structure

src/peer/mod.rs

@@ -1,9 +1,10 @@
-pub mod default_peer;
-pub use default_peer::*;
-
-pub mod download_peer;
+mod default_peer;
+mod download_peer;
 pub mod listen;
 
+// Re-export commonly used items
+pub use default_peer::{DefaultPeer, PeerOperation};
+
 use crate::message::Message;
 use core::fmt;
 use std::str::FromStr;