refactor(app): 移除分类和详情模块，新增云开发测试页

- 从项目中删除分类页及相关代码和样式文件
- 从项目中删除详情页及相关代码和样式文件
- 首页简化为欢迎界面并添加跳转云开发测试页入口
- 更新自定义底部栏移除分类入口
- 更新app.js初始化云开发环境
- 修改app.json移除分类页面配置
- 调整首页样式和交互，提高简洁度
- 配置云函数目录路径cloudfunctionRoot为cloudfunctions/

pages/index/index.wxss

@@ -1,145 +1,33 @@
 /* pages/index/index.wxss */
 
 .container {
-  padding-bottom: 120rpx;
+  min-height: 100vh;
+  background-color: #f5f5f5;
+  padding: 30rpx;
+  box-sizing: border-box;
 }
 
-/* 搜索栏 */
-.search-bar {
-  position: sticky;
-  top: 0;
-  z-index: 100;
-  background-color: #fff;
+.welcome-section {
+  text-align: center;
+  padding: 60rpx 0;
 }
 
-/* 轮播图 */
-.banner-section {
-  padding: 20rpx;
-}
-
-.banner-swiper {
-  height: 300rpx;
-  border-radius: 16rpx;
-  overflow: hidden;
-}
-
-.banner-image {
-  width: 100%;
-  height: 100%;
-}
-
-/* 分类 */
-.category-section {
-  margin-top: 0;
-}
-
-.category-grid {
-  display: flex;
-  flex-wrap: wrap;
-}
-
-.category-item {
-  width: 25%;
-  display: flex;
-  flex-direction: column;
-  align-items: center;
-  padding: 20rpx 0;
-}
-
-.category-icon {
-  width: 80rpx;
-  height: 80rpx;
-  border-radius: 50%;
-  background-color: #e6f7ff;
-  display: flex;
-  align-items: center;
-  justify-content: center;
-  margin-bottom: 12rpx;
-}
-
-.category-name {
-  font-size: 24rpx;
-  color: #333;
-}
-
-/* 信息列表 */
-.info-section {
-  margin-top: 20rpx;
-}
-
-.section-header {
-  padding: 20rpx 30rpx;
-  display: flex;
-  justify-content: space-between;
-  align-items: center;
-}
-
-.section-title {
-  font-size: 32rpx;
+.welcome-title {
+  display: block;
+  font-size: 44rpx;
   font-weight: bold;
   color: #333;
-}
-
-.info-item {
-  margin-top: 0;
-  margin-bottom: 20rpx;
-}
-
-.info-content {
-  display: flex;
-  justify-content: space-between;
-}
-
-.info-text {
-  flex: 1;
-  margin-right: 20rpx;
-  display: flex;
-  flex-direction: column;
-}
-
-.info-title {
-  font-size: 30rpx;
-  font-weight: 500;
-  color: #333;
-  line-height: 1.5;
-  margin-bottom: 12rpx;
-}
-
-.info-summary {
-  font-size: 26rpx;
-  color: #666;
-  line-height: 1.5;
   margin-bottom: 16rpx;
 }
 
-.info-meta {
-  display: flex;
-  align-items: center;
-  margin-top: auto;
-}
-
-.info-time {
-  font-size: 22rpx;
+.welcome-subtitle {
+  display: block;
+  font-size: 28rpx;
   color: #999;
-  margin-left: 16rpx;
 }
 
-.info-views {
-  font-size: 22rpx;
-  color: #999;
-  margin-left: 16rpx;
-}
-
-/* 加载状态 */
-.loading-section {
-  display: flex;
-  justify-content: center;
-  padding: 40rpx;
-}
-
-.no-more {
-  text-align: center;
-  padding: 40rpx;
-  color: #999;
-  font-size: 24rpx;
+.menu-section {
+  margin-top: 40rpx;
+  border-radius: 16rpx;
+  overflow: hidden;
 }