feat(calendar): enhance event handling with timezone support and filtering capabilities

frontend/src/locales/zh.json

@@ -691,5 +691,19 @@
   },
   "google_maps": {
     "google_maps_integration_desc": "连接您的Google Maps帐户以获取高质量的位置搜索结果和建议。"
+  },
+  "calendar": {
+    "all_categories": "所有类别",
+    "all_day_event": "全天活动",
+    "calendar_overview": "日历概述",
+    "categories": "类别",
+    "day": "天",
+    "events_scheduled": "预定事件",
+    "filter_by_category": "按类别过滤",
+    "filtered_results": "过滤结果",
+    "month": "月",
+    "today": "今天",
+    "total_events": "总事件",
+    "week": "星期"
   }
 }