Add master display UI with audio output management and styling

- Implement main.js for the master display functionality, including WebSocket connection, audio output management, and state handling.
- Create style.css for the master display's visual design, ensuring a cohesive look and feel with a dark theme and responsive layout.
- Integrate device management with a fallback for non-Electron environments, allowing users to select audio outputs.
- Add features for managing favorites, including toggling favorites and filtering by genre.
- Enhance user experience with a responsive favorites grid and drag-to-scroll functionality.

web/shared/ws.js

@@ -1,13 +1,18 @@
-export function connectWs(onMessage) {
+export function connectWs(onMessage, opts = {}) {
     let ws, retry = 0, closed = false;
     function open() {
         const proto = location.protocol === 'https:' ? 'wss' : 'ws';
-        ws = new WebSocket(`${proto}://${location.host}/ws`);
-        ws.addEventListener('open', () => { retry = 0; });
+        const params = new URLSearchParams();
+        if (opts.room) params.set('room', opts.room);
+        if (opts.kind) params.set('kind', opts.kind);
+        const qs = params.toString();
+        ws = new WebSocket(`${proto}://${location.host}/ws${qs ? '?' + qs : ''}`);
+        ws.addEventListener('open', () => { retry = 0; opts.onOpen?.(); });
         ws.addEventListener('message', (ev) => {
             try { onMessage(JSON.parse(ev.data)); } catch { }
         });
         ws.addEventListener('close', () => {
+            opts.onClose?.();
             if (closed) return;
             retry = Math.min(retry + 1, 6);
             setTimeout(open, 500 * 2 ** retry);
@@ -17,6 +22,7 @@ export function connectWs(onMessage) {
     open();
     return {
         send(msg) { if (ws?.readyState === WebSocket.OPEN) ws.send(JSON.stringify(msg)); },
-        close() { closed = true; ws?.close(); }
+        close() { closed = true; ws?.close(); },
+        get readyState() { return ws?.readyState; }
     };
 }