Join one FM-Funknetz talk group from a headset window.

The station reads ~/.funknetz.json, speaks protocol 2.0, and builds an unsigned funknetz.app.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/dist/index.html

@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <title>funknetz</title>
+  <link rel="stylesheet" href="app.css">
+</head>
+<body>
+  <main>
+    <p id="connection">Disconnected</p>
+    <p>Callsign <span id="callsign"></span></p>
+    <p>Talk group <span id="talkgroup"></span></p>
+    <p id="detail">Idle</p>
+    <button id="ptt" type="button">Push to talk</button>
+  </main>
+  <script src="app.js"></script>
+</body>
+</html>