fix: preserve vault fields and align cipher compatibility

Preserve linked and unknown encrypted fields in Web edits, reject stale and concurrent saves, and support official bulk delete and restore methods while retaining legacy routes.

Add 20 offline compatibility regressions and update undici to 8.10.2. Verified 51 tests, TypeScript checks, locale validation, Web build and Worker deployment dry run. The unpatched braces advisory remains visible.

webapp/src/lib/i18n/locales/zh-TW.ts

@@ -1090,6 +1090,7 @@ const zhTW: Record<string, string> = {
   "txt_remove_device_failed": "移除設備失敗",
   "txt_remove_all_devices_failed": "移除所有設備失敗",
   "txt_update_item_failed": "更新項目失敗",
+  "txt_item_changed_elsewhere": "項目已在其他用戶端修改。你的編輯內容仍保留在表單中，請複製需要的修改，重新開啟項目後再儲存。",
   "txt_update_send_failed": "更新 Send 失敗",
   "txt_update_user_status_failed": "更新用戶狀態失敗",
   "txt_use_recovery_code": "使用恢復代碼",