Hello,
your rule already is IN the Repository. Why call a web script if your rule can already contain the logic you need to execute? If you want to avoid duplication of code, simply extract logic to a JS library file which you can include in your rule JS via <blockcode><import resource=""></blockcode>.
If you really must, you may be able to make the "remote" object available by reconfiguring the Spring context. Simply add <blockcode><entry key="remote" value-ref="webframework.webscripts.scriptremote" /></blockcode> as a "scriptObject" to the bean "webscripts.container". Best you copy the bean from web-scripts-application-context.xml into an override in your extension directory.
You may also have to add a <blockcode><alfresco-config></blockcode> config file for configuring the "Remote" endpoints.
Again: You do not need "remote" to execute Repository code - simply use a JavaScript library file for common code. Using "remote" to call a Repository web script is like trying to call yourself on your phone to tell yourself to do something you could instead be doing already…
Regards
Axel