feat(logs): add auto-update toggle to Access Logs and Logs viewers

A checkbox in both the Xray Access Logs and panel Logs modals polls the
existing refresh every 5s while enabled, respecting the current row count,
level/filter, and Direct/Blocked/Proxy selections. The poller tears down on
close or untoggle. Adds a localized pages.index.autoUpdate key to all 13 locales.

internal/web/translation/zh-CN.json

@@ -246,6 +246,7 @@
       "dontRefresh": "安装中，请勿刷新此页面",
       "logs": "日志",
       "accessLogs": "访问日志",
+      "autoUpdate": "自动更新",
       "config": "配置",
       "backup": "备份",
       "backupTitle": "备份和恢复",