fix: remove student AI assistant navigation

src/layout/components/Sidebar/index.vue

@@ -294,7 +294,6 @@ const sidebarStyle = computed(() => {
   };
 });
 const studentCourseNav = [
-  { title: "AI智能助手", path: "/assistant/index", activePrefix: "/assistant" },
   {
     title: "互联网产品开发基础",
     children: [
@@ -394,7 +393,6 @@ const trainingTaskKeyByPath = {
   "/assessment/diagnosis": "product-diagnosis-iteration",
 };
 const studentCourseBaseNav = [
-  { title: "AI智能助手", path: "/assistant/index", activePrefix: "/assistant" },
   { title: "考试考核", path: "/examination/index", activePrefix: "/examination" },
 ];
 const studentTaskSections = ref([]);
@@ -402,7 +400,6 @@ const currentCourseNav = computed(() => (isTeacherRole.value
   ? filterTeacherManageNavigation(teacherManageNav)
   : [...studentCourseBaseNav, ...studentTaskSections.value]));
 const studentIconByPath = {
-  "/assistant/index": "MagicStick",
   "/comprehensive/index": "School",
   "/foundation/new-product-survey": "Search",
   "/foundation/product-development-factors": "SetUp",