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.

web/shared/dom.js

@@ -0,0 +1,17 @@
+export function el(tag, props = {}, ...children) {
+  const node = document.createElement(tag);
+  for (const [k, v] of Object.entries(props || {})) {
+    if (k === 'class') node.className = v;
+    else if (k === 'style' && typeof v === 'object') Object.assign(node.style, v);
+    else if (k.startsWith('on') && typeof v === 'function') node.addEventListener(k.slice(2).toLowerCase(), v);
+    else if (k === 'html') node.innerHTML = v;
+    else if (v !== false && v != null) node.setAttribute(k, v === true ? '' : v);
+  }
+  for (const c of children.flat()) {
+    if (c == null || c === false) continue;
+    node.appendChild(c instanceof Node ? c : document.createTextNode(String(c)));
+  }
+  return node;
+}
+
+export function clear(node) { while (node.firstChild) node.removeChild(node.firstChild); }