fix(multiplayer): reconcile authoritative initial connections

server/cmd/game-server-supervisor/main.go

@@ -39,6 +39,7 @@ func main() {
 	sdkBaseURL := options.String("sdk-base-url", "", "Agones SDK REST base URL; empty enables direct mode")
 	readyURL := options.String("ready-url", "", "explicit process-ready probe URL")
 	drainURL := options.String("drain-url", "", "loopback drain URL")
+	admissionURL := options.String("initial-connect-ready-url", "", "authenticated loopback URL that starts the initial-connect clock after durable assignment readiness")
 	drainTokenEnv := options.String("drain-token-env", "COSMIC_CLASH_DRAIN_TOKEN", "environment variable containing the drain bearer token")
 	transport := options.String("transport", "enet", "enet or steam_sdr")
 	grace := options.Duration("drain-grace", supervisor.DefaultDrainGrace, "maximum graceful drain duration")
@@ -64,6 +65,7 @@ func main() {
 		SDKBaseURL:   *sdkBaseURL,
 		ReadyURL:     *readyURL,
 		DrainURL:     *drainURL,
+		AdmissionURL: *admissionURL,
 		DrainToken:   token,
 		Transport:    *transport,
 		ReadyTimeout: 30 * time.Second,