fix: harden import auth and utility page copy

templates/admin/ppt_audit_preview.html

@@ -10,9 +10,9 @@
 <div class="container-fluid mt-3">
   <section class="ppt-preview-hero">
     <div>
-      <div class="ppt-preview-kicker"><i class="fas fa-file-powerpoint me-1"></i>PPT Online Preview</div>
+      <div class="ppt-preview-kicker"><i class="fas fa-file-powerpoint me-1"></i>簡報線上預覽</div>
       <h1 class="ppt-preview-title">{{ filename }}</h1>
-      <p class="ppt-preview-subtitle">檔案大小 {{ file_size_kb }} KB · 修改時間 {{ file_mtime }} · 預覽以 PDF 快取呈現，原始 PPTX 仍可下載。</p>
+      <p class="ppt-preview-subtitle">檔案大小 {{ file_size_kb }} KB · 修改時間 {{ file_mtime }} · 預覽以 PDF 快取呈現，簡報檔仍可下載。</p>
     </div>
     <div class="ppt-preview-actions">
       <a class="btn btn-outline-secondary btn-sm" href="{{ back_url }}"><i class="fas fa-angle-left me-1"></i>回產線</a>
@@ -34,13 +34,13 @@
   </p>
   {% else %}
   <section class="ppt-preview-empty">
-    <div class="ppt-preview-kicker"><i class="fas fa-triangle-exclamation me-1"></i>Preview unavailable</div>
+    <div class="ppt-preview-kicker"><i class="fas fa-triangle-exclamation me-1"></i>預覽暫時不可用</div>
     <h2>目前無法產生線上預覽</h2>
     <p>{{ preview.error or '轉檔流程沒有回傳可用 PDF。' }}</p>
     <div class="ppt-preview-diagnostics">
-      <span>需要容器內可執行 LibreOffice / soffice</span>
-      <span>部署後會用 PDF 快取避免每次重轉</span>
-      <span>原始 PPTX 可先下載檢查</span>
+      <span>轉檔服務尚未就緒</span>
+      <span>完成後會保留 PDF 預覽</span>
+      <span>可先下載簡報檔檢查</span>
     </div>
   </section>
   {% endif %}