Clean up warnings: remove dead code, unused imports

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

crates/core/src/http.rs

@@ -7,7 +7,7 @@ use std::net::{IpAddr, SocketAddr};
 use std::sync::Arc;
 
 use tokio::io::{AsyncReadExt, AsyncWriteExt};
-use tokio::net::{TcpListener, TcpStream};
+use tokio::net::TcpStream;
 use tokio::sync::Mutex;
 use tracing::{debug, info};