feat(cloudflare): worker-hosted version.json for UI updates

packages/cloudflare/src/index.ts

@@ -0,0 +1,29 @@
+export interface Env {
+  ASSETS: { fetch: (request: Request) => Promise<Response> }
+}
+
+function withHeader(response: Response, key: string, value: string): Response {
+  const headers = new Headers(response.headers)
+  headers.set(key, value)
+  return new Response(response.body, {
+    status: response.status,
+    statusText: response.statusText,
+    headers,
+  })
+}
+
+export default {
+  async fetch(request: Request, env: Env): Promise<Response> {
+    const url = new URL(request.url)
+
+    if (url.pathname === "/version.json") {
+      const assetResponse = await env.ASSETS.fetch(request)
+
+      // Ensure this stays fresh; the server uses it on startup.
+      const withCache = withHeader(assetResponse, "Cache-Control", "no-cache")
+      return withHeader(withCache, "Content-Type", "application/json; charset=utf-8")
+    }
+
+    return new Response("Not found", { status: 404 })
+  },
+}