feat: add node/status filters and custom date range to traffic page

- Add NodeFilter component with flag emojis and checkbox dropdown
- Add StatusFilter component with colored status dots
- Add custom date range picker (calendar toggle, from/to date inputs)
- Wire all filters to backend params (nodes, statuses, start_date, end_date)
- CSV export passes all active filters and date range
- Add displayNodes memo for table column filtering
- Add i18n keys for nodes, statuses, dates in ru/en/zh/fa

src/locales/zh.json

@@ -685,7 +685,18 @@
       "loading": "正在加载流量数据...",
       "noTariff": "\u2014",
       "search": "按名称或用户名搜索",
-      "allTariffs": "所有套餐"
+      "allTariffs": "所有套餐",
+      "nodes": "节点",
+      "allNodes": "所有节点",
+      "status": "状态",
+      "allStatuses": "全部",
+      "statusActive": "活跃",
+      "statusTrial": "试用",
+      "statusExpired": "已过期",
+      "statusDisabled": "已禁用",
+      "customDates": "自定义日期",
+      "dateFrom": "从",
+      "dateTo": "到"
     },
     "paymentMethods": {
       "title": "支付方法",