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/fa.json

@@ -685,7 +685,18 @@
       "loading": "در حال بارگذاری داده‌های ترافیک...",
       "noTariff": "\u2014",
       "search": "جستجو بر اساس نام یا نام کاربری",
-      "allTariffs": "همه تعرفه‌ها"
+      "allTariffs": "همه تعرفه‌ها",
+      "nodes": "نودها",
+      "allNodes": "همه نودها",
+      "status": "وضعیت",
+      "allStatuses": "همه",
+      "statusActive": "فعال",
+      "statusTrial": "آزمایشی",
+      "statusExpired": "منقضی",
+      "statusDisabled": "غیرفعال",
+      "customDates": "تاریخ دلخواه",
+      "dateFrom": "از",
+      "dateTo": "تا"
     },
     "emailTemplates": {
       "title": "قالب‌های ایمیل",