Add player functionality with HLS support and API integration

- Implemented a new Player class in player.js to handle audio playback, including HLS support using hls.js.
- Created a shared API module in api.js for making HTTP requests with proper error handling.
- Added DOM utility functions in dom.js for creating and clearing elements.
- Introduced WebSocket connection handling in ws.js for real-time updates.
- Developed a comprehensive CSS stylesheet for styling the application, including a high-contrast theme.

server/streams/probe.js

@@ -0,0 +1,68 @@
+// Low-level stream probe.
+// Icecast/SHOUTcast servers commonly answer with `ICY 200 OK` instead of
+// `HTTP/1.1 200 OK`, which Node's built-in fetch refuses to parse. We open
+// a raw TCP/TLS socket, send a minimal HTTP/1.0 GET, and inspect the first
+// status line ourselves.
+
+import net from 'node:net';
+import tls from 'node:tls';
+
+const TIMEOUT = 8000;
+const UA = 'Mozilla/5.0 OnlineRadioExplorer/0.1';
+
+export function probeStream(rawUrl) {
+  return new Promise((resolve) => {
+    let url;
+    try { url = new URL(rawUrl); } catch { return resolve('err-badurl'); }
+
+    const isTls  = url.protocol === 'https:';
+    const port   = Number(url.port) || (isTls ? 443 : 80);
+    const path   = (url.pathname || '/') + (url.search || '');
+    const host   = url.hostname;
+
+    const opts = { host, port, servername: host };
+    const connect = isTls ? tls.connect : net.connect;
+    const sock = connect(opts);
+
+    let settled = false;
+    const finish = (status) => {
+      if (settled) return;
+      settled = true;
+      try { sock.destroy(); } catch {}
+      resolve(status);
+    };
+
+    sock.setTimeout(TIMEOUT);
+    sock.on('timeout', () => finish('err-timeout'));
+    sock.on('error',   () => finish('err-fetch'));
+
+    sock.on('connect', () => {
+      const req =
+        `GET ${path} HTTP/1.0\r\n` +
+        `Host: ${host}\r\n` +
+        `User-Agent: ${UA}\r\n` +
+        `Icy-MetaData: 1\r\n` +
+        `Accept: */*\r\n` +
+        `Connection: close\r\n\r\n`;
+      sock.write(req);
+    });
+
+    let buf = '';
+    sock.on('data', (chunk) => {
+      buf += chunk.toString('latin1');
+      const eol = buf.indexOf('\n');
+      if (eol < 0) return;
+      const statusLine = buf.slice(0, eol).trim();
+      // Accept: HTTP/1.x 2xx, ICY 2xx, SOURCE 2xx
+      const m = statusLine.match(/^(?:HTTP\/\d\.\d|ICY|SOURCE)\s+(\d{3})/i);
+      if (!m) return finish(`bad-${statusLine.slice(0, 16)}`);
+      const code = Number(m[1]);
+      if (code >= 200 && code < 400) finish('up');
+      else finish(`http-${code}`);
+    });
+
+    sock.on('end', () => {
+      if (!settled) finish(buf ? 'err-empty' : 'err-fetch');
+    });
+  });
+}