chore(前端): 删掉三个从 ojnext 搬来就没人用的文件

阶段 1 是「原样搬入、不改业务代码」，所以 ojnext 里已经死掉的东西也一起
搬了过来。这三个文件全仓零引用：

- utils/permissions.ts（usePermissions / checkRoutePermission）
- oj/ai/components/StreakStats.vue
- shared/components/IconButton.vue

确认方式：在 apps/web 全部 .ts / .vue / .json / .html / .js 里搜这五个名字
（排除文件自身）零命中；两个组件也不在自动生成的 components.d.ts 里，
permissions.ts 的两个导出同样不在 auto-imports.d.ts 里 —— 也就是说
它们连自动导入的注册都没拿到，不存在「模板里隐式用到」的可能。

permissions.ts 在 ojnext 里也是死的，不是搬运过程产生的。

vue-tsc 0 error，vite build 通过。

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

apps/web/src/utils/permissions.ts

@@ -1,108 +0,0 @@
-import { useUserStore } from "shared/store/user"
-
-export function usePermissions() {
-  const userStore = useUserStore()
-
-  return {
-    isAuthenticated: computed(() => userStore.isAuthed),
-    isAdminRole: computed(() => userStore.isAdminRole),
-    isTeacherOrAbove: computed(() => userStore.isTeacherOrAbove),
-    isSuperAdmin: computed(() => userStore.isSuperAdmin),
-    hasProblemPermission: computed(() => userStore.hasProblemPermission),
-
-    canManageUsers: computed(() => userStore.isSuperAdmin),
-    canManageAnnouncements: computed(() => userStore.isSuperAdmin),
-    canManageTutorials: computed(() => userStore.isSuperAdmin),
-    canManageSystemConfig: computed(() => userStore.isSuperAdmin),
-    canSendMessages: computed(() => userStore.isSuperAdmin),
-
-    canManageProblems: computed(() => userStore.hasProblemPermission),
-    canManageContests: computed(() => userStore.isTeacherOrAbove),
-    canManageProblemsets: computed(() => userStore.isTeacherOrAbove),
-    canViewClassroomData: computed(() => userStore.isTeacherOrAbove),
-
-    canManageAllProblems: computed(
-      () =>
-        userStore.user?.problemPermission === "All" || userStore.isSuperAdmin,
-    ),
-    canManageOwnProblems: computed(
-      () =>
-        userStore.user?.problemPermission === "Own" && !userStore.isSuperAdmin,
-    ),
-
-    getUserPermissionLevel: computed(() => {
-      if (userStore.isSuperAdmin) return "超级管理员"
-      if (userStore.isTeacherAdmin) return "教师管理员"
-      if (userStore.isStudentAdmin) return "学生管理员"
-      return "普通用户"
-    }),
-
-    getProblemPermissionLevel: computed(() => {
-      if (!userStore.user) return "无权限"
-      switch (userStore.user.problemPermission) {
-        case "All":
-          return "管理所有题目"
-        case "Own":
-          return "管理自己的题目"
-        case "None":
-          return "无题目权限"
-        default:
-          return "无权限"
-      }
-    }),
-  }
-}
-
-export function checkRoutePermission(routeName: string): boolean {
-  const userStore = useUserStore()
-
-  const superAdminRoutes = [
-    "admin home",
-    "admin config",
-    "admin user list",
-    "admin user generate",
-    "admin announcement list",
-    "admin announcement create",
-    "admin announcement edit",
-    "admin message list",
-    "admin tutorial list",
-    "admin tutorial create",
-    "admin tutorial edit",
-  ]
-
-  const teacherAdminRoutes = [
-    "admin contest list",
-    "admin contest create",
-    "admin contest edit",
-    "admin contest problem list",
-    "admin contest problem create",
-    "admin contest problem edit",
-    "admin contest helper",
-    "admin problemset list",
-    "admin problemset create",
-    "admin problemset edit",
-    "admin problemset detail",
-    "admin stuck problems",
-    "admin top ac trend",
-  ]
-
-  const problemPermissionRoutes = [
-    "admin problem list",
-    "admin problem create",
-    "admin problem edit",
-  ]
-
-  if (superAdminRoutes.includes(routeName)) {
-    return userStore.isSuperAdmin
-  }
-
-  if (teacherAdminRoutes.includes(routeName)) {
-    return userStore.isTeacherOrAbove
-  }
-
-  if (problemPermissionRoutes.includes(routeName)) {
-    return userStore.hasProblemPermission
-  }
-
-  return true
-}