feat(frontend): add confirmation dialog before deleting users, peers, and interfaces (#654)

* feat(frontend): add confirmation dialog before deleting users, peers, and interfaces (#652)

Add a browser confirm() dialog to the delete functions in UserEditModal,
PeerEditModal, and InterfaceEditModal to prevent accidental deletions.
The bulk-delete actions in UserView already had this protection; this
change brings single-item deletion in line with that behavior.

Translation keys (confirm-delete) added for all 10 supported locales:
de, en, es, fr, ko, pt, ru, uk, vi, zh.

Signed-off-by: LeC-D <leo.openc@gmail.com>

* fix broken translation files

---------

Signed-off-by: LeC-D <leo.openc@gmail.com>
Co-authored-by: Christoph Haas <christoph.h@sprinternet.at>

frontend/src/lang/translations/zh.json

@@ -242,6 +242,7 @@
           "label": "管理员"
         }
       },
+      "confirm-delete": "确定要删除用户“{id}”吗？",
       "interface-view": {
         "headline": "接口配置: "
       },
@@ -353,7 +354,8 @@
             "placeholder": "持久保持连接 (0 = 默认)"
           }
         },
-        "button-apply-defaults": "应用节点默认值"
+        "button-apply-defaults": "应用节点默认值",
+        "confirm-delete": "确定要删除接口“{id}”吗？"
       },
       "peer-view": {
         "headline-peer": "节点: ",
@@ -469,7 +471,8 @@
         },
         "expires-at": {
           "label": "过期日期"
-        }
+        },
+        "confirm-delete": "确定要删除对等点“{id}”吗？"
       },
       "peer-multi-create": {
         "headline-peer": "创建多个节点",