fix(自学): 手机上读课好读多了：长代码不再被截掉半行（折行接着缩进），表格不再一字一行，填空的注释不再折成像另一行代码、空也大了；往下读时底栏收起、读到课末不再有两个「下一课」；点下一课落在新课开头而不是末尾；输出预测不再把同一个问题问两遍

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/web/src/oj/learn/components/CodeRunBlock.vue

@@ -10,6 +10,8 @@ import { explainRuntimeError } from "oj/problem/utils/runtimeError"
 import { useAuthModalStore } from "shared/store/authModal"
 import { useUserStore } from "shared/store/user"
 import { mainWrapExtensions, wrapMain } from "../wrapMain"
+import { hangWrapExtensions } from "../hangIndent"
+import { useBreakpoints } from "shared/composables/breakpoints"
 
 const CodeEditor = defineAsyncComponent(() => import("shared/components/CodeEditor.vue"))
 
@@ -35,7 +37,12 @@ const message = useMessage()
 const { copy } = useClipboard({ legacy: true })
 
 const original = computed(() => (props.wrapMain ? wrapMain(props.code) : props.code))
-const extensions = computed(() => (props.wrapMain ? mainWrapExtensions : []))
+const { isDesktop } = useBreakpoints()
+// 手机上折行（见 hangIndent.ts）；桌面正文 720 宽，长行少，照旧横着滚
+const extensions = computed(() => [
+  ...(props.wrapMain ? mainWrapExtensions : []),
+  ...(isDesktop.value ? [] : hangWrapExtensions),
+])
 const value = ref(original.value)
 const input = ref("")
 const running = ref(false)