feat: add metrics, observability, test fixtures, and scaling playbook artifacts

frontend/src/main.ts

@@ -18,7 +18,16 @@ let username = "viewer" + Math.floor(Math.random() * 1000);
 let chatVisible = true;
 const onlineUsers = new Set<string>();
 
-function resolveWebSocketBaseUrl() {
+export function resetViewerStateForTests() {
+  hls = null;
+  ws = null;
+  currentRoom = "main";
+  username = "viewer";
+  chatVisible = true;
+  onlineUsers.clear();
+}
+
+export function resolveWebSocketBaseUrl() {
   const configuredUrl = import.meta.env.VITE_PUBLIC_WS_URL?.trim();
 
   if (configuredUrl) {
@@ -29,7 +38,7 @@ function resolveWebSocketBaseUrl() {
   return `${protocol}//${window.location.host}/ws`;
 }
 
-function resolveManifestUrl() {
+export function resolveManifestUrl() {
   const configuredUrl = import.meta.env.VITE_PUBLIC_HLS_URL?.trim();
   const cacheBust = `stream=${Date.now()}`;
   const sameOriginManifestUrl = new URL("/hls/playlist.m3u8", window.location.origin);
@@ -139,7 +148,7 @@ async function refreshSchedule() {
   }
 }
 
-async function initPlayerAndChat() {
+export async function initPlayerAndChat(loadHlsModule: () => Promise<{ default: HlsClass }> = () => import("hls.js")) {
   const video = document.getElementById("player") as HTMLVideoElement;
   const manifestUrl = resolveManifestUrl();
 
@@ -148,7 +157,7 @@ async function initPlayerAndChat() {
     video.addEventListener("loadedmetadata", () => video.play());
   } else {
     try {
-      const { default: Hls } = await import("hls.js");
+      const { default: Hls } = await loadHlsModule();
       if (Hls.isSupported()) {
         hls = new Hls();
         hls.loadSource(manifestUrl);