caddy: netbird proxy to k3s, flush_interval fixes, transport tuning

scripts/caddyreload

@@ -1,2 +1,3 @@
 caddy_container_id=$(docker ps | grep caddy | awk '{print $1;}')
 docker exec -w /etc/caddy $caddy_container_id caddy reload
+docker exec -w /etc/caddy $caddy_container_id caddy fmt --overwrite