refactor: restructure project into 5 core modules

Organize project by 5 core modules based on requirement docs.

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

components/platform-nav.tsx

@@ -0,0 +1,58 @@
+"use client"
+
+import Link from "next/link"
+import { usePathname } from 'next/navigation'
+import { LayoutDashboard, Database, Users, DollarSign, Brain, Settings, Home } from 'lucide-react'
+import { cn } from "@/lib/utils"
+
+const navItems = [
+  { href: "/platform/dashboard", icon: LayoutDashboard, label: "平台总览" },
+  { href: "/platform/data-management", icon: Database, label: "数据管理" },
+  { href: "/platform/user-portrait", icon: Users, label: "用户画像" },
+  { href: "/platform/value-assessment", icon: DollarSign, label: "价值评估" },
+  { href: "/platform/ai-assistant", icon: Brain, label: "AI助手" },
+]
+
+export default function PlatformNav() {
+  const pathname = usePathname()
+
+  return (
+    <nav className="fixed left-0 top-0 h-screen w-64 bg-white border-r border-gray-200 p-6">
+      <div className="mb-8">
+        <h2 className="text-2xl font-bold text-gray-900 mb-1">神射手</h2>
+        <p className="text-sm text-gray-600">数据资产中台</p>
+      </div>
+
+      <div className="space-y-2">
+        <Link
+          href="/"
+          className="flex items-center gap-3 px-4 py-3 rounded-lg transition-colors text-gray-600 hover:bg-gray-100 hover:text-gray-900"
+        >
+          <Home className="w-5 h-5" />
+          <span className="font-medium">返回首页</span>
+        </Link>
+        
+        {navItems.map((item) => {
+          const Icon = item.icon
+          const isActive = pathname === item.href
+
+          return (
+            <Link
+              key={item.href}
+              href={item.href}
+              className={cn(
+                "flex items-center gap-3 px-4 py-3 rounded-lg transition-colors",
+                isActive
+                  ? "bg-blue-50 text-blue-600 font-semibold"
+                  : "text-gray-600 hover:bg-gray-100 hover:text-gray-900"
+              )}
+            >
+              <Icon className="w-5 h-5" />
+              <span className="font-medium">{item.label}</span>
+            </Link>
+          )
+        })}
+      </div>
+    </nav>
+  )
+}