chore: 清理最近活动(recentActivities)后端接口和前端翻译

frontend/src/plugins/i18n/en.json

@@ -952,8 +952,6 @@
     "recentTicketsDesc": "Recent ticket records",
     "userDistribution": "User Distribution",
     "userDistributionDesc": "Global user geographic distribution",
-    "recentActivities": "Recent Activities",
-    "recentActivitiesDesc": "Your recent operation records",
     "allRecentActivities": "All Recent Activities",
     "allRecentActivitiesDesc": "All your operation records",
     "china": "China",

frontend/src/plugins/i18n/zh.json

@@ -953,8 +953,6 @@
     "recentTicketsDesc": "最近的工单记录",
     "userDistribution": "用户分布",
     "userDistributionDesc": "全球用户地理分布",
-    "recentActivities": "最近活动",
-    "recentActivitiesDesc": "您最近的操作记录",
     "allRecentActivities": "所有最近活动",
     "allRecentActivitiesDesc": "您所有的操作记录",
     "china": "中国",