refactor(courses): 移除未使用的搜索和模糊处理函数，优化搜索逻辑

移除CoursesPage.vue中未使用的handleSearch和handleBlur函数，简化代码结构。在CourseListPage.vue中引入防抖函数优化搜索性能，并统一处理搜索操作，提升代码可维护性。

 <!--
  * @Date: 2025-03-21 14:31:21
  * @LastEditors: hookehuyr hookehuyr@gmail.com
- * @LastEditTime: 2025-04-15 14:24:16
+ * @LastEditTime: 2025-05-21 16:57:36
  * @FilePath: /mlaj/src/views/courses/CourseListPage.vue
  * @Description: 文件描述
 -->
@@ -39,6 +39,7 @@ import { courses as mockCourses } from '@/utils/mockData';
 // 导入接口
 import { getCourseListAPI } from "@/api/course";
 import { List } from 'vant';
+import { useDebounceFn } from '@vueuse/core';
 
 const $route = useRoute();
 const courses = ref([]);
@@ -48,35 +49,35 @@ const limit = ref(5);
 const page = ref(0);
 const keyword = ref('');
 
-// 搜索课程列表
-const searchCourses = async () => {
-  const res = await getCourseListAPI({ limit: limit.value, page: 0, keyword: keyword.value });
+// 防抖处理的搜索课程列表
+const debouncedSearch = useDebounceFn(async (searchKeyword) => {
+  const res = await getCourseListAPI({ limit: limit.value, page: 0, keyword: searchKeyword });
   if (res.code) {
     courses.value = res.data;
     finished.value = res.data.length < limit.value;
     page.value = 1;
   }
+}, 300);
+
+// 统一处理搜索操作
+const handleSearch = (newKeyword) => {
+  if (keyword.value !== newKeyword) {
+    keyword.value = newKeyword;
+    debouncedSearch(newKeyword);
+  }
 };
 
 // 监听路由参数变化
-// watchEffect(() => {
-//   const queryKeyword = $route.query.keyword;
-//   if (keyword.value !== queryKeyword) {
-//     keyword.value = queryKeyword || '';
-//     searchCourses();
-//   }
-// });
-
-// Search handler
-// const handleSearch = (query) => {
-  // keyword.value = query;
-  // searchCourses();
-// };
+watchEffect(() => {
+  const queryKeyword = $route.query.keyword;
+  if (queryKeyword !== undefined) {
+    handleSearch(queryKeyword || '');
+  }
+});
 
 // Blur handler
 const handleBlur = (query) => {
-  keyword.value = query;
-  searchCourses();
+  handleSearch(query);
 };
 
 // Load more courses

@@ -3,7 +3,7 @@
     <div class="pb-16">
       <!-- Search Bar -->
       <div class="pb-2">
-        <SearchBar placeholder="搜索" @search="handleSearch" @blur="handleBlur" :isCoursePage="true" />
+        <SearchBar placeholder="搜索" :isCoursePage="true" />
       </div>
 
       <!-- Featured Course Banner -->
@@ -107,17 +107,6 @@ const $route = useRoute();
 const $router = useRouter();
 useTitle($route.meta.title);
 
-// Search handler
-const handleSearch = (query) => {
-  console.log("Searching for:", query);
-  // Would implement actual search logic here
-};
-// Blur handler
-const handleBlur = (query) => {
-  // 实际项目中这里会调用搜索API
-  console.log('Searching for:', query);
-};
-
 // Current time for the countdown timer
 const todayDate = new Date();
 const formattedTime = featuredCourse.liveTime.split(":");