refactor: overhaul UI for streamlined user experience

Redesign navigation, home overview, user portrait, and valuation pages
with improved functionality and responsive design.

Co-authored-by: null <4804959+fnvtk@users.noreply.github.com>

components/user-pool/user-pool-header.tsx

@@ -0,0 +1,27 @@
+import { Button } from "@/components/ui/button"
+import { PlusCircle, Download, Upload } from "lucide-react"
+
+export function UserPoolHeader() {
+  return (
+    <div className="flex flex-col md:flex-row justify-between items-start md:items-center space-y-4 md:space-y-0">
+      <div>
+        <h1 className="text-2xl font-bold tracking-tight">用户池管理</h1>
+        <p className="text-muted-foreground">管理和分析您的用户资产，发掘用户价值</p>
+      </div>
+      <div className="flex items-center space-x-2">
+        <Button variant="outline" size="sm">
+          <Upload className="mr-2 h-4 w-4" />
+          导入
+        </Button>
+        <Button variant="outline" size="sm">
+          <Download className="mr-2 h-4 w-4" />
+          导出
+        </Button>
+        <Button size="sm">
+          <PlusCircle className="mr-2 h-4 w-4" />
+          添加用户
+        </Button>
+      </div>
+    </div>
+  )
+}