✨ feat: Host a relay on Hetzner (#114)

We are hosting a [MoQ](https://quic.video) relay on a remote (bare
metal) server on Hetzner

With a lot of help from @victorpahuus

packages/moq/playback/worker/message.ts

@@ -0,0 +1,98 @@
+import { GroupHeader } from "../../transport/objects"
+import { RingShared } from "../../common/ring"
+
+export interface Config {
+	audio?: ConfigAudio
+	video?: ConfigVideo
+}
+
+export interface ConfigAudio {
+	channels: number
+	sampleRate: number
+
+	ring: RingShared
+}
+
+export interface ConfigVideo {
+	canvas: OffscreenCanvas
+}
+
+export interface Init {
+	name: string // name of the init object
+	data: Uint8Array
+}
+
+export interface Segment {
+	init: string // name of the init object
+	kind: "audio" | "video"
+	header: GroupHeader
+	buffer: Uint8Array
+	stream: ReadableStream<Uint8Array>
+}
+
+/*
+export interface Play {
+	// Start playback once the minimum buffer size has been reached.
+	minBuffer: number
+}
+
+export interface Seek {
+	timestamp: number
+}
+*/
+
+// Sent periodically with the current timeline info.
+export interface Timeline {
+	// The current playback position
+	timestamp?: number
+
+	// Audio specific information
+	audio: TimelineAudio
+
+	// Video specific information
+	video: TimelineVideo
+}
+
+export interface TimelineAudio {
+	buffer: Range[]
+}
+
+export interface TimelineVideo {
+	buffer: Range[]
+}
+
+export interface Range {
+	start: number
+	end: number
+}
+
+// Used to validate that only the correct messages can be sent.
+
+// Any top level messages that can be sent to the worker.
+export interface ToWorker {
+	// Sent to configure on startup.
+	config?: Config
+
+	// Sent on each init/data stream
+	init?: Init
+	segment?: Segment
+
+	/*
+	// Sent to control playback
+	play?: Play
+	seek?: Seek
+	*/
+}
+
+// Any top-level messages that can be sent from the worker.
+export interface FromWorker {
+	// Sent back to the main thread regularly to update the UI
+	timeline?: Timeline
+}
+
+/*
+interface ToWorklet {
+	config?: Audio.Config
+}
+
+*/