Fix types in Svelte adapter (#2005)

* Export ResolvedComponent type

* Make setup callback optional for when in SSR mode

Author: pedroborges

packages/svelte/src/createInertiaApp.ts

@@ -12,7 +12,7 @@ type AppComponent = ComponentType<App> & { render: () => SvelteRenderResult }
 interface CreateInertiaAppProps {
   id?: string
   resolve: ComponentResolver
-  setup: (props: {
+  setup?: (props: {
     el: Element
     App: ComponentType<App>
     props: {

packages/svelte/src/index.ts

@@ -4,4 +4,5 @@ export { default as createInertiaApp } from './createInertiaApp'
 export { default as inertia } from './link'
 export { default as page } from './page'
 export { default as remember } from './remember'
+export { type ResolvedComponent } from './types'
 export { default as useForm, type InertiaForm, type InertiaFormProps } from './useForm'