use composables.

src/oj/problem/components/ProblemInfo.vue

@@ -1,7 +1,7 @@
 <script setup lang="ts">
 import { DIFFICULTY } from "utils/constants"
 import { getACRate, getTagColor, parseTime } from "utils/functions"
-import { isDesktop } from "utils/breakpoints"
+import { isDesktop } from "~/shared/composables/breakpoints"
 import { Problem } from "utils/types"
 
 interface Props {