platform: modularize api/gui, add docs-tests-web foundation, and refresh root config

selective-vpn-api/app/transport_backends_adapter_systemd_provision.go

@@ -0,0 +1,13 @@
+package app
+
+func (transportSystemdBackend) Provision(client TransportClient) transportBackendActionResult {
+	inputs, preOut, preErr, failure := buildTransportSystemdProvisionInputs(client)
+	if failure != nil {
+		return *failure
+	}
+	if failure = writeTransportSystemdProvisionUnits(client, inputs); failure != nil {
+		return *failure
+	}
+	res := finalizeTransportSystemdProvision(client, inputs, preOut, preErr)
+	return res
+}