feat: add delete backup functionality with confirmation dialog

src/i18n/locales/en.json

@@ -308,7 +308,17 @@
       "rename": "Rename",
       "renameSuccess": "Backup renamed",
       "renameFailed": "Rename failed",
-      "namePlaceholder": "Enter new name"
+      "namePlaceholder": "Enter new name",
+      "createBackup": "Backup Now",
+      "creating": "Backing up...",
+      "createSuccess": "Backup created successfully",
+      "createFailed": "Backup failed",
+      "delete": "Delete",
+      "deleting": "Deleting...",
+      "deleteSuccess": "Backup deleted",
+      "deleteFailed": "Delete failed",
+      "deleteConfirmTitle": "Confirm Delete",
+      "deleteConfirmMessage": "This backup will be permanently deleted. This action cannot be undone."
     },
     "webdavSync": {
       "title": "WebDAV Cloud Sync",

src/i18n/locales/ja.json

@@ -308,7 +308,17 @@
       "rename": "名前変更",
       "renameSuccess": "バックアップの名前を変更しました",
       "renameFailed": "名前変更に失敗しました",
-      "namePlaceholder": "新しい名前を入力"
+      "namePlaceholder": "新しい名前を入力",
+      "createBackup": "今すぐバックアップ",
+      "creating": "バックアップ中...",
+      "createSuccess": "バックアップが作成されました",
+      "createFailed": "バックアップに失敗しました",
+      "delete": "削除",
+      "deleting": "削除中...",
+      "deleteSuccess": "バックアップを削除しました",
+      "deleteFailed": "削除に失敗しました",
+      "deleteConfirmTitle": "バックアップの削除を確認",
+      "deleteConfirmMessage": "このバックアップは完全に削除されます。この操作は取り消せません。"
     },
     "webdavSync": {
       "title": "WebDAV クラウド同期",

src/i18n/locales/zh.json

@@ -308,7 +308,17 @@
       "rename": "重命名",
       "renameSuccess": "备份重命名成功",
       "renameFailed": "重命名失败",
-      "namePlaceholder": "输入新名称"
+      "namePlaceholder": "输入新名称",
+      "createBackup": "立即备份",
+      "creating": "备份中...",
+      "createSuccess": "备份创建成功",
+      "createFailed": "备份创建失败",
+      "delete": "删除",
+      "deleting": "删除中...",
+      "deleteSuccess": "备份已删除",
+      "deleteFailed": "删除失败",
+      "deleteConfirmTitle": "确认删除备份",
+      "deleteConfirmMessage": "此备份将被永久删除，此操作无法撤消。"
     },
     "webdavSync": {
       "title": "WebDAV 云同步",