fix(web): stop spurious page refresh on account menu open; plugin log auto-refresh as switch

Two unrelated frontend fixes:

- LanguageSelector mounts each time the sidebar account dropdown opens and
  unconditionally called i18n.changeLanguage() on mount, emitting a
  languageChanged event even when the language was unchanged. That handed
  every useTranslation() consumer a fresh `t` reference, re-running effects
  keyed on `t` (e.g. the plugins page system-status fetch) and surfacing as
  a page "refresh". Guard the call so it only fires on an actual change.

- Plugin logs auto-refresh control changed from a toggle Button to a
  Switch + Label; the on/off button i18n keys are replaced by a single
  static logsAutoRefresh label across all 8 locales.

web/src/i18n/locales/vi-VN.ts

@@ -599,8 +599,7 @@ const viVN = {
     tabLogs: 'Nhật ký',
     logsLevelAll: 'Tất cả cấp độ',
     logsRefresh: 'Làm mới',
-    logsAutoRefreshOn: 'Tự động làm mới: Bật',
-    logsAutoRefreshOff: 'Tự động làm mới: Tắt',
+    logsAutoRefresh: 'Tự động làm mới',
     logsEmpty:
       'Chưa có nhật ký. Nhật ký do plugin in qua logger sẽ hiển thị ở đây.',
     fileUpload: {