feat: 实现自适应路由切换，根据 User-Agent 及屏幕大小自动导航 PC/Mobile 视图

frontend/src/router/mobileHost.ts

@@ -2,12 +2,72 @@ export function isMobileHost(hostname = window.location.hostname) {
   return hostname === "m.localhost" || hostname.startsWith("m.");
 }
 
-export function toMobilePath(path: string) {
-  if (path === "/") {
+export function isMobileDevice() {
+  if (typeof window === "undefined" || !window.navigator) return false;
+  const ua = window.navigator.userAgent;
+  const isMobileUA = /Android|webOS|iPhone|iPad|iPod|BlackBerry|IEMobile|Opera Mini/i.test(ua);
+  const isSmallScreen = window.innerWidth < 768;
+  return isMobileUA || isSmallScreen;
+}
+
+export function getMobilePath(path: string): string {
+  if (path === "/" || path === "") {
     return "/m";
   }
-  if (path === "/m" || path.startsWith("/m/") || path.startsWith("/admin")) {
+  if (path.startsWith("/m") || path.startsWith("/admin")) {
     return path;
   }
+  
+  if (path === "/listings" || path.startsWith("/listings/")) {
+    return `/m${path}`;
+  }
+  if (path === "/orders" || path.startsWith("/orders/")) {
+    return `/m${path}`;
+  }
+  if (path === "/realname") return "/m/realname";
+  if (path === "/login") return "/m/login";
+  if (path === "/register") return "/m/register";
+  
+  if (path === "/seller/listings/create") {
+    return "/m/seller/listings/create";
+  }
+  
+  // PC-only views that don't have mobile counterparts go to mobile profile as fallback
+  if (path === "/wallet" || path === "/notifications" || path.startsWith("/seller")) {
+    return "/m/profile";
+  }
+  
   return `/m${path}`;
 }
+
+export function getPcPath(path: string): string {
+  if (!path.startsWith("/m") || path.startsWith("/admin")) {
+    return path;
+  }
+  
+  if (path === "/m" || path === "/m/") {
+    return "/";
+  }
+  
+  const subPath = path.substring(2);
+  
+  if (subPath === "/listings" || subPath.startsWith("/listings/")) {
+    return subPath;
+  }
+  if (subPath === "/orders" || subPath.startsWith("/orders/")) {
+    return subPath;
+  }
+  if (subPath === "/login") return "/login";
+  if (subPath === "/register") return "/login"; // PC uses /login for both auth actions
+  if (subPath === "/realname") return "/realname";
+  if (subPath === "/seller/listings/create") return "/seller/listings/create";
+  
+  if (subPath === "/messages") return "/";
+  if (subPath === "/profile") return "/wallet";
+  
+  return subPath || "/";
+}
+
+export function toMobilePath(path: string) {
+  return getMobilePath(path);
+}