fix: make user dropdown to be fixed (#1148)

components/user/UserDropdown.vue

@@ -1,5 +1,5 @@
 <template>
-  <VDropdown :distance="0" placement="top-start">
+  <VDropdown :distance="0" placement="top-start" strategy="fixed">
     <button btn-action-icon :aria-label="$t('action.switch_account')">
       <div :class="{ 'hidden xl:block': currentUser }" i-ri:more-2-line />
       <AccountAvatar v-if="currentUser" xl:hidden :account="currentUser.account" w-9 h-9 square />