feat(public-frontend): 新增联系我们页面

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

public-frontend/src/App.tsx

@@ -1,10 +1,11 @@
 import { useEffect, useState } from "react";
-import { Boxes, Search, PlusCircle, Code2, KeyRound } from "lucide-react";
+import { Boxes, Search, PlusCircle, Code2, KeyRound, Headset } from "lucide-react";
 import Home from "./components/Home";
 import ProductView from "./components/ProductView";
 import Contribute from "./components/Contribute";
 import ApiDocs from "./components/ApiDocs";
 import Account from "./components/Account";
+import Contact from "./components/Contact";
 import { api } from "./api";
 
 type View =
@@ -12,13 +13,15 @@ type View =
   | { name: "product"; id: string }
   | { name: "contribute" }
   | { name: "api" }
-  | { name: "account" };
+  | { name: "account" }
+  | { name: "contact" };
 
 const NAV: { key: View["name"]; label: string; icon: typeof Search }[] = [
   { key: "home", label: "检索", icon: Search },
   { key: "contribute", label: "贡献档案", icon: PlusCircle },
   { key: "api", label: "API", icon: Code2 },
   { key: "account", label: "API 密钥", icon: KeyRound },
+  { key: "contact", label: "联系我们", icon: Headset },
 ];
 
 export default function App() {
@@ -88,6 +91,7 @@ export default function App() {
         )}
         {view.name === "api" && <ApiDocs onRegister={() => setView({ name: "account" })} />}
         {view.name === "account" && <Account />}
+        {view.name === "contact" && <Contact />}
       </main>
 
       <footer className="border-t border-gray-200/70 bg-white/60">
@@ -109,6 +113,12 @@ export default function App() {
             >
               API 调用说明
             </button>
+            <button
+              onClick={() => setView({ name: "contact" })}
+              className="ml-1 text-brand-600 font-medium hover:underline"
+            >
+              联系我们
+            </button>
           </p>
           <div className="mt-3">
             <a