Rewrite dashboard and overlay, single /events stream, static client served by the backend

Backend: one SSE stream for messages, selection, poll and connection status; reconnect with backoff; no on-disk Innertube session cache; mock only with MOCK_CHAT=1; binds to 127.0.0.1; serves client/out so production runs on one port. Full URLs for links YouTube truncates in chat.

Client: components split out, Lucide icons, stream title and status, on-air strip, search, pause, keyboard shortcuts, overlay settings dialog. Overlay themes, position, size, animation and auto-hide via URL, sized for 1080p and scaled with the source. New blueprint theme for the brand background.

Removed Tailwind, better-sqlite3, zod, the timezone helpers, Cline memory bank and AGENTS.md. Added ESLint, node:test tests and CI.

client/lib/imageProxy.ts

@@ -1,27 +1,17 @@
-const BACKEND_URL = process.env.NEXT_PUBLIC_BACKEND_URL ?? 'http://localhost:4100';
+import { BACKEND_URL } from './config';
 
-/**
- * Converts a YouTube CDN image URL to use our backend proxy
- * This prevents 429 rate limit errors from YouTube's CDN
- */
+const PROXIED_HOSTS = new Set(['yt3.ggpht.com', 'yt4.ggpht.com', 'i.ytimg.com', 'lh3.googleusercontent.com']);
+
+/** Routes YouTube CDN images through the backend cache so OBS and the dashboard do not hit CDN rate limits. */
 export function proxyImageUrl(url: string | undefined): string | undefined {
   if (!url) return undefined;
-  
-  // Check if it's a YouTube CDN URL
-  const youtubeCdnDomains = ['yt3.ggpht.com', 'yt4.ggpht.com', 'i.ytimg.com'];
-  
   try {
-    const urlObj = new URL(url);
-    if (youtubeCdnDomains.includes(urlObj.hostname)) {
-      // Proxy through our backend
+    const parsed = new URL(url);
+    if (PROXIED_HOSTS.has(parsed.hostname)) {
       return `${BACKEND_URL}/proxy/image?url=${encodeURIComponent(url)}`;
     }
   } catch {
-    // If URL parsing fails, return as-is
     return url;
   }
-  
-  // Return non-YouTube URLs as-is
   return url;
 }
-