Audio: "Tap to enable audio" overlay when context is suspended

Instead of silently dropping notes or hoping gesture listeners fire,
show a clear overlay on first packet if AudioContext is suspended.
One tap resumes context and removes overlay. Standard pattern used
by every browser game/music site.

public/audio.js

@@ -88,11 +88,13 @@
 
   function sonifyPacket(pkt) {
     if (!audioEnabled || !currentVoice) return;
-    // Lazy-init AudioContext on first actual packet (may not have user gesture,
-    // but browser will auto-resume when it gets one)
     if (!audioCtx) initAudio();
     if (!audioCtx) return;
-    if (audioCtx.state === 'suspended') audioCtx.resume();
+    if (audioCtx.state === 'suspended') {
+      // Show unlock overlay if not already showing
+      _showUnlockOverlay();
+      return; // don't schedule notes on suspended context
+    }
     if (activeVoices >= MAX_VOICES) return;
 
     const parsed = parsePacketBytes(pkt);
@@ -175,22 +177,28 @@
     const savedVoice = localStorage.getItem('live-audio-voice');
     if (savedVoice) setVoice(savedVoice);
 
-    // If audio was enabled, create context now and try to resume.
-    // Browsers with prior engagement will auto-allow; gesture listener is fallback.
+    // If audio was enabled, create context eagerly. If browser suspends it,
+    // the unlock overlay will appear when the first packet arrives.
     if (audioEnabled) {
       initAudio();
-      const unlockAudio = () => {
-        if (audioCtx && audioCtx.state === 'suspended') audioCtx.resume();
-        document.removeEventListener('click', unlockAudio, true);
-        document.removeEventListener('touchstart', unlockAudio, true);
-        document.removeEventListener('keydown', unlockAudio, true);
-      };
-      document.addEventListener('click', unlockAudio, true);
-      document.addEventListener('touchstart', unlockAudio, true);
-      document.addEventListener('keydown', unlockAudio, true);
     }
   }
 
+  let _overlayShown = false;
+
+  function _showUnlockOverlay() {
+    if (_overlayShown) return;
+    _overlayShown = true;
+    const overlay = document.createElement('div');
+    overlay.className = 'audio-unlock-overlay';
+    overlay.innerHTML = '<div class="audio-unlock-prompt">🔊 Tap to enable audio</div>';
+    overlay.addEventListener('click', () => {
+      if (audioCtx) audioCtx.resume();
+      overlay.remove();
+    }, { once: true });
+    document.body.appendChild(overlay);
+  }
+
   // Export engine + helpers for voice modules
   window.MeshAudio = {
     sonifyPacket,

public/index.html

@@ -22,7 +22,7 @@
   <meta name="twitter:title" content="MeshCore Analyzer">
   <meta name="twitter:description" content="Real-time MeshCore LoRa mesh network analyzer — live packet visualization, node tracking, channel decryption, and route analysis.">
   <meta name="twitter:image" content="https://raw.githubusercontent.com/Kpa-clawbot/meshcore-analyzer/master/public/og-image.png">
-  <link rel="stylesheet" href="style.css?v=1774199178">
+  <link rel="stylesheet" href="style.css?v=1774200683">
   <link rel="stylesheet" href="home.css">
   <link rel="stylesheet" href="live.css?v=1774058575">
   <link rel="stylesheet" href="https://unpkg.com/leaflet@1.9.4/dist/leaflet.css"
@@ -90,7 +90,7 @@
   <script src="nodes.js?v=1774126708" onerror="console.error('Failed to load:', this.src)"></script>
   <script src="traces.js?v=1774135052" onerror="console.error('Failed to load:', this.src)"></script>
   <script src="analytics.js?v=1774126708" onerror="console.error('Failed to load:', this.src)"></script>
-  <script src="audio.js?v=1774200474" onerror="console.error('Failed to load:', this.src)"></script>
+  <script src="audio.js?v=1774200683" onerror="console.error('Failed to load:', this.src)"></script>
   <script src="audio-v1-constellation.js?v=1774199178" onerror="console.error('Failed to load:', this.src)"></script>
   <script src="live.js?v=1774199178" onerror="console.error('Failed to load:', this.src)"></script>
   <script src="observers.js?v=1774290000" onerror="console.error('Failed to load:', this.src)"></script>

public/style.css

@@ -1640,3 +1640,31 @@ tr[data-hops]:hover { background: rgba(59,130,246,0.1); }
   color: #00ff41 !important;
   border-color: #00ff4130 !important;
 }
+
+/* Audio unlock overlay */
+.audio-unlock-overlay {
+  position: fixed;
+  inset: 0;
+  z-index: 10000;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  background: rgba(0,0,0,0.6);
+  cursor: pointer;
+  -webkit-tap-highlight-color: transparent;
+}
+.audio-unlock-prompt {
+  background: #1f2937;
+  color: #e5e7eb;
+  padding: 24px 40px;
+  border-radius: 12px;
+  font-size: 20px;
+  font-weight: 600;
+  box-shadow: 0 4px 24px rgba(0,0,0,0.5);
+  user-select: none;
+}
+.matrix-theme .audio-unlock-prompt {
+  background: #001a00;
+  color: #00ff41;
+  box-shadow: 0 0 30px rgba(0,255,65,0.2);
+}