refactor: 移除二维码和交叉编译，改为列出所有 LAN IP 地址；清理依赖

internal/server/net.go

@@ -5,17 +5,21 @@ import (
 	"net"
 )
 
-// GetLANIP returns the first non-loopback IPv4 address.
-func GetLANIP() (string, error) {
+// GetLANIPs returns all non-loopback IPv4 addresses.
+func GetLANIPs() ([]string, error) {
 	addrs, err := net.InterfaceAddrs()
 	if err != nil {
-		return "", err
+		return nil, err
 	}
+	var ips []string
 	for _, addr := range addrs {
 		if ipNet, ok := addr.(*net.IPNet); ok && !ipNet.IP.IsLoopback() && ipNet.IP.To4() != nil {
-			return ipNet.IP.String(), nil
+			ips = append(ips, ipNet.IP.String())
 		}
 	}
-	return "", fmt.Errorf("no LAN IP found")
+	if len(ips) == 0 {
+		return nil, fmt.Errorf("no LAN IP found")
+	}
+	return ips, nil
 }