refactor: remove forward auth, move module net/http to net/gphttp

internal/net/gphttp/loadbalancer/round_robin.go

@@ -0,0 +1,22 @@
+package loadbalancer
+
+import (
+	"net/http"
+	"sync/atomic"
+)
+
+type roundRobin struct {
+	index atomic.Uint32
+}
+
+func (*LoadBalancer) newRoundRobin() impl        { return &roundRobin{} }
+func (lb *roundRobin) OnAddServer(srv Server)    {}
+func (lb *roundRobin) OnRemoveServer(srv Server) {}
+
+func (lb *roundRobin) ServeHTTP(srvs Servers, rw http.ResponseWriter, r *http.Request) {
+	index := lb.index.Add(1) % uint32(len(srvs))
+	srvs[index].ServeHTTP(rw, r)
+	if lb.index.Load() >= 2*uint32(len(srvs)) {
+		lb.index.Store(0)
+	}
+}