Stabilize MCP ingress log capture test

apps/mcp-server/src/main.rs

@@ -595,9 +595,8 @@ mod tests {
                 .compact()
                 .with_filter(LevelFilter::INFO),
         );
-        let dispatch = tracing::Dispatch::new(subscriber);
 
-        let _guard = tracing::dispatcher::set_default(&dispatch);
+        let _ = tracing::subscriber::set_global_default(subscriber);
         let response = post_jsonrpc_response(
             &client,
             &mcp_url,
@@ -622,7 +621,10 @@ mod tests {
         assert_eq!(response.status(), reqwest::StatusCode::OK);
 
         let logs = writer.output();
-        assert!(logs.contains("mcp request received"));
+        assert!(
+            logs.contains("mcp request received"),
+            "captured logs did not include ingress marker: {logs}"
+        );
         assert!(logs.contains("req_mcp_trace_123"));
         assert!(logs.contains("sales-request-trace"));
         assert!(logs.contains("default"));