Set 'base' on build but leave base empty '' in dev.

[Dilden]

svelte.config.js should have this set for builds to work in a subdirectory

kit: {
    paths: {
        base: '/helth'
    },
}

[Dilden]

Due to problems with CORS, some application features will need to make API calls to backend which means the app can simply be hosted at "/". No longer necessary to host static files in a subdirectory as a nodeJS backend is where the app will be deployed to.