HMR not working in ServerComponents using the Data Mode template

[bskimball]

When updating a ServerComponent in Dev mode, vite sends "rsc:update" to the browser to signify a change. React Router tries to re-validate using window.__router.revalidate(), but throws an error that window.__router is undefined

entry.browser.tsx:50 Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'revalidate')
    at entry.browser.tsx:50:62
    at client:132:48
    at Array.map (<anonymous>)
    at HMRClient.notifyListeners (client:132:36)
    at handleMessage (client:961:23)
    at Object.promise (client:490:43)
    at Queue.dequeue (client:516:10)
    at client:518:12
    at <anonymous>

[bskimball]

The fix for this is in closed PR #166. This is where we assign the payload.router to the window.__router variable.

		if (payload.type === "render") {
			// @ts-expect-error - router exists on render payload
			(window as any).__router = payload.router;
		}