fix(ui): sort headers alphabetically in diagram detail panel

ui/src/components/ExecutionDiagram/tabs/HeadersTab.tsx

@@ -18,7 +18,7 @@ function parseHeaders(json: string | undefined): Record<string, string> {
 }
 
 function HeaderTable({ headers }: { headers: Record<string, string> }) {
-  const entries = Object.entries(headers);
+  const entries = Object.entries(headers).sort(([a], [b]) => a.localeCompare(b));
   if (entries.length === 0) {
     return <div className={styles.emptyState}>No headers</div>;
   }