fix: sync IMAP language with parent view

Co-authored-by: factory-droid[bot] <138933559+factory-droid[bot]@users.noreply.github.com>

Author: margbug01-cyber

mail-viewer/imap-mail-app/public/index.html

@@ -1143,6 +1143,15 @@ <h3 data-i18n="modalTitle">连接 IMAP 邮箱</h3>
   });
 }
 
+window.addEventListener('message', function(event) {
+  if (event.origin !== window.location.origin) return;
+  if (event.data?.type === 'manymail-lang-change' && event.data.lang) {
+    currentLang = event.data.lang === 'en' ? 'en' : 'zh';
+    localStorage.setItem('manymail-lang', currentLang);
+    applyLang();
+  }
+});
+
 async function api(method, url, body) {
   const opts = { method, headers: {} };
   if (body) {

mail-viewer/templates/index.html

@@ -772,6 +772,13 @@ <h5 class="modal-title" id="composeModalLabel"><i class="bi bi-pencil-square me-
             currentLang = currentLang === 'zh' ? 'en' : 'zh';
             localStorage.setItem('manymail-lang', currentLang);
             applyLang();
+            const imapFrame = document.getElementById('imap-frame');
+            try {
+                imapFrame?.contentWindow?.postMessage({
+                    type: 'manymail-lang-change',
+                    lang: currentLang,
+                }, window.location.origin);
+            } catch (e) {}
             // re-render dynamic content
             if (currentMessages.length > 0 && currentTab === 'inbox') renderMessages(currentMessages);
             if (currentSentMessages.length > 0 && currentTab === 'sent') renderSentMessages(currentSentMessages);