Add lease-bound Remote key IPC and SDK validation

sdk/go/tentacle/session.go

@@ -180,7 +180,8 @@ func (client *SessionClient) write(output io.Writer) {
 
 // Call has a two-second maximum deadline. Timeout/cancellation retires the
 // session, so an abandoned effect cannot leave unbounded pending calls behind.
-// The host currently implements remote.open, remote.close and remote.heartbeat.
+// Typed desktop operations require separately attached reader owners; a
+// successful call acknowledges admission, not delivery to a desktop/backend.
 func (client *SessionClient) Call(ctx context.Context, method string, params any, result any) error {
 	if ctx == nil {
 		return errors.New("nil session call context")