feat: 完成navbar隐藏优化和侧边栏冻结功能

- 优化navbar滚动隐藏逻辑，更敏感响应
- 添加返回顶部按钮，固定在右下角
- 实现profile页面侧边栏真正冻结效果
- 修复首页滑动指示器位置
- 优化整体布局确保首屏内容完整显示

prisma/schema.prisma

@@ -0,0 +1,14 @@
+// This is your Prisma schema file,
+// learn more about it in the docs: https://pris.ly/d/prisma-schema
+
+// Looking for ways to speed up your queries, or scale easily with your serverless or edge functions?
+// Try Prisma Accelerate: https://pris.ly/cli/accelerate-init
+
+generator client {
+  provider = "prisma-client"
+  output   = "../src/generated/prisma"
+}
+
+datasource db {
+  provider = "postgresql"
+}