fix(screenshare): enable button feedback, audio capture fallback and bump version

public/app.js

@@ -119,7 +119,7 @@ function leaveVoice(reason) {
   if (S.ws) { try { S.ws.close(); } catch {} S.ws = null; }
   if (S.micStream) { S.micStream.getTracks().forEach((t) => t.stop()); S.micStream = null; }
   els.mic.disabled = false;
-  $('#btn-share').disabled = true;
+  // Keep btn-share enabled so clicking it prompts the user to join a channel
   updateMicButton();
   document.querySelectorAll('.channel.voice').forEach((c) => c.classList.remove('active'));
   S.room = null;
@@ -388,21 +388,52 @@ function orientListener() {
 // screen share (local)
 // ---------------------------------------------------------------------------
 async function startScreenShare() {
-  if (S.sharing || !S.room) return;
+  if (S.sharing) {
+    stopScreenShare();
+    return;
+  }
+  if (!S.room) {
+    toast('Join a voice channel first to share your screen', 'warn');
+    return;
+  }
+  if (!navigator.mediaDevices || !navigator.mediaDevices.getDisplayMedia) {
+    toast('Screen sharing is not supported in this browser or context', 'error');
+    return;
+  }
   let stream;
   try {
+    // Try requesting display media with audio first
     stream = await navigator.mediaDevices.getDisplayMedia({
       video: { frameRate: 30 }, audio: true,
     });
-  } catch {
-    return; // user cancelled
+  } catch (err) {
+    // If user cancelled / denied, don't toast as error unless it's not NotAllowedError/AbortError
+    if (err.name === 'NotAllowedError' || err.name === 'AbortError') {
+      return;
+    }
+    // Try fallback without audio constraint if audio failed
+    try {
+      stream = await navigator.mediaDevices.getDisplayMedia({
+        video: { frameRate: 30 },
+      });
+    } catch (fallbackErr) {
+      if (fallbackErr.name === 'NotAllowedError' || fallbackErr.name === 'AbortError') {
+        return;
+      }
+      console.error('Failed to get display media:', fallbackErr);
+      toast(`Could not share screen: ${fallbackErr.message || fallbackErr}`, 'error');
+      return;
+    }
   }
   S.screenStream = stream;
   S.sharing = true;
   send({ type: 'state', state: { muted: S.muted, deafened: S.deafened, sharing: true } });
 
   for (const peer of S.peers.values()) addScreenToPeer(peer);
-  stream.getVideoTracks()[0].addEventListener('ended', () => stopScreenShare());
+  const videoTrack = stream.getVideoTracks()[0];
+  if (videoTrack) {
+    videoTrack.addEventListener('ended', () => stopScreenShare());
+  }
   renderScreens();
   renderTiles();
   $('#btn-share').classList.add('active');
@@ -823,7 +854,7 @@ window.addEventListener('keydown', (ev) => {
   if (ev.target.tagName === 'INPUT' || ev.target.tagName === 'TEXTAREA') return;
   if (ev.key === 'm') toggleMic();
   if (ev.key === 'd') toggleDeafen();
-  if (ev.key === 's' && S.room) $('#btn-share').click();
+  if (ev.key === 's') $('#btn-share').click();
 });
 window.addEventListener('beforeunload', () => { try { leaveVoice(); } catch {} });
 

public/index.html

@@ -46,7 +46,7 @@
       <div class="user-buttons">
         <button id="btn-mic" class="ctl" title="Toggle mic (M)">&#127908;</button>
         <button id="btn-deafen" class="ctl" title="Toggle deafen (D)">&#128064;</button>
-        <button id="btn-share" class="ctl" title="Share your screen" disabled>&#128421;&#65039;</button>
+        <button id="btn-share" class="ctl" title="Share your screen (S)">&#128421;&#65039;</button>
         <button id="btn-settings" class="ctl" title="Voice &amp; ICE settings">&#9881;&#65039;</button>
       </div>
     </footer>
@@ -97,6 +97,6 @@
 
 <div id="toasts"></div>
 
-<script src="app.js?v=6"></script>
+<script src="app.js?v=7"></script>
 </body>
 </html>