fix(mci): Fix ClassCastException in GlowMciComponent mock by instantiating resBodyClass

dap-was-lib/src/main/java/io/shinhanlife/glow/communication/module/mci/component/GlowMciComponent.java

@@ -11,8 +11,18 @@ public class GlowMciComponent<S, R> {
     
     public Transfer<R> sync(Transfer<S> request) {
         // 실제 Glow HTTP 통신 (GlowHttpHeaderUtil, HttpClient 등) 수행 시뮬레이션
+        Object responseBody = new Object();
+        if (request != null && request.getResBodyClass() != null) {
+            try {
+                responseBody = request.getResBodyClass().getDeclaredConstructor().newInstance();
+            } catch (Exception e) {
+                // Ignore and fallback to Object
+            }
+        }
+        
         return (Transfer<R>) Transfer.builder()
-                .body(new Object())
+                .header(request != null ? request.getHeader() : null)
+                .body(responseBody)
                 .build();
     }
 }