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/next.config.js

@@ -1,11 +1,10 @@
 /** @type {import('next').NextConfig} */
 const nextConfig = {
   reactStrictMode: true,
-  experimental: {
-    serverActions: {
-      bodySizeLimit: '2mb'
-    }
-  }
+  // Static export: the backend serves `client/out` so production runs on a single port.
+  output: 'export',
+  trailingSlash: true,
+  images: { unoptimized: true }
 };
 
 module.exports = nextConfig;