fix: harden service websocket reconnect flows

Stabilize the service console and callback-host websocket paths so idle disconnects and mid-task client drops no longer wedge task execution or spam repeated commands.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/bin/sg_claw_client.rs

@@ -83,6 +83,7 @@ fn run() -> Result<(), String> {
                             eprintln!("busy: {message}");
                             break;
                         }
+                        ServiceMessage::Pong => {}
                     }
                 }
                 Message::Close(_) => {