OpenAPI 스펙 내보내기(UI/DL) 기능 추가

- 내보내기 활성화 여부 설정 키 추가(EXPORT_ENABLED_KEY)
- JSP/JS: 내보내기 버튼 및 다운로드 로직 연동
- YAML/JSON 포맷 저장 기능 구현

WebContent/jsp/onl/transaction/apim/djbApiSpecManPopup.jsp

@@ -69,6 +69,7 @@
       gwAddress: "${gwAddress}",
       useProxy: ${useProxy},
       tokenUseProxy: ${tokenUseProxy},
+      exportEnabled: ${exportEnabled},
       orgPopupUrl: "<c:url value='/onl/transaction/apim/apiSpecMan.view'/>",
       groupPopupUrl: "<c:url value='/onl/transaction/apim/djbApiSpecMan.view'/>?cmd=GROUP_POPUP",
       jsonUrl: "<c:url value='/onl/transaction/apim/djbApiSpecMan.json'/>"
@@ -93,6 +94,8 @@
         <button id="btn-newwin" class="hidden px-3 py-1.5 text-sm rounded border border-slate-300 bg-white hover:bg-slate-50">새창으로 띄우기</button>
         <button id="btn-regen" class="px-3 py-1.5 text-sm rounded border border-slate-300 bg-white hover:bg-slate-50">자동 생성(초기화)</button>
         <button id="btn-save" class="px-3 py-1.5 text-sm rounded bg-emerald-600 text-white hover:bg-emerald-700">저장</button>
+        <%-- 내보내기 버튼은 PTL_PROPERTY(djb.openapi.export.enabled=true) 일 때만 노출. 기본 미노출. --%>
+        <c:if test="${exportEnabled}">
         <div class="relative">
           <button id="btn-export" class="px-3 py-1.5 text-sm rounded bg-brand-600 text-white hover:bg-brand-700">내보내기 ▾</button>
           <div id="export-menu" class="hidden absolute right-0 mt-1 w-44 bg-white border border-slate-200 rounded shadow-lg z-40">
@@ -100,6 +103,7 @@
             <button data-export="json" class="block w-full text-left px-3 py-2 text-sm hover:bg-slate-50">JSON 다운로드</button>
           </div>
         </div>
+        </c:if>
         <button id="btn-close" class="px-3 py-1.5 text-sm rounded border border-slate-300 bg-white hover:bg-slate-50">닫기</button>
       </div>
     </header>