Native video: render others' screen-share on native calls

Last native-video gap: on a native (iOS) call the WebView has no LiveKit
connection, so a screen shared by a web/desktop participant never rendered.
The mesh already flips the sharer's tile into the big "stage" (meeting-
peer-screen -> meetSharers -> sharing-mode), so extend the tile sync: each
tile now carries a `screen` flag (meetSharers.has(id)). The plugin renders
that participant's screen-share track (source .screenShareVideo) on the
tile with layoutMode .fit (contain, no crop) instead of the camera.

Outgoing screen-share from iOS is still unsupported (no getDisplayMedia /
ReplayKit broadcast extension) — toggleScreen now shows a clear toast on
native instead of silently failing.

Needs a Codemagic build (plugin change). Web deployed.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

mobile/plugins/native-call/ios/Sources/NativeCallPlugin/NativeCallPlugin.swift

@@ -140,6 +140,14 @@ public class NativeCallPlugin: CAPPlugin, CAPBridgedPlugin, PKPushRegistryDelega
         return pub.track as? VideoTrack
     }
 
+    // The remote screen-share track for a user id — nil if they aren't sharing (or it isn't subscribed yet).
+    // (Local screen-share isn't supported on iOS — no ReplayKit broadcast extension — so this is remote-only.)
+    private func screenTrack(forUid uid: String) -> VideoTrack? {
+        guard let room = room, let p = room.remoteParticipants[Participant.Identity(from: uid)] else { return nil }
+        guard let pub = p.videoTracks.first(where: { $0.source == .screenShareVideo && !$0.isMuted && $0.track != nil }) else { return nil }
+        return pub.track as? VideoTrack
+    }
+
     private func tileKey(uid: String, isLocal: Bool) -> String { isLocal ? "__local" : uid }
 
     private func removeAllTileViews() {
@@ -337,10 +345,15 @@ public class NativeCallPlugin: CAPPlugin, CAPBridgedPlugin, PKPushRegistryDelega
                 let x = num("x"), y = num("y"), w = num("w"), h = num("h")
                 if w < 2 || h < 2 { continue }
                 let key = self.tileKey(uid: uid, isLocal: isLocal)
-                guard let track = self.cameraTrack(forUid: uid, isLocal: isLocal) else { continue } // camera off → leave the web avatar
+                // A tile flagged `screen` is a sharer's stage tile → show their screen-share track (fit, so it
+                // isn't cropped); otherwise the camera (fill). Either is nil when off → web avatar shows.
+                let wantScreen = (t["screen"] as? Bool) ?? false
+                guard let track = wantScreen ? self.screenTrack(forUid: uid)
+                                             : self.cameraTrack(forUid: uid, isLocal: isLocal) else { continue }
                 wanted.insert(key)
                 let vv = self.tileViews[key] ?? self.makeTileView(host: host, key: key)
                 if vv.superview !== host { host.addSubview(vv) }
+                vv.layoutMode = wantScreen ? .fit : .fill
                 if vv.track !== track { vv.track = track }
                 vv.frame = CGRect(x: x, y: y, width: w, height: h)
                 // Native video covers the web tile, so redraw the essentials (name + muted) natively.

server/public/home.html

@@ -5221,6 +5221,7 @@ function meetMakePeer(peerId, name){
 // (no extra tiles, the peer's video just shows the screen). Falls back to addTrack+renegotiate if
 // no video sender exists yet (camera never turned on). Stopping restores the camera (or avatar).
 async function toggleScreen(){
+  if(meetNative){ toast('Sharing your screen from iPhone isn’t supported yet — but you’ll see others’ shared screens.'); return; } // iOS has no getDisplayMedia / ReplayKit ext wired
   if(meetScreen){ stopScreen(); return; }
   if(!meetMultiShare && meetSharers.size>0){ toast('Someone is already sharing their screen'); return; }
   if(SFU.on){
@@ -5378,11 +5379,11 @@ function bzNativeSyncTiles(){
   document.querySelectorAll('#meetGrid .meet-tile').forEach(el=>{
     const id=el.id ? el.id.replace('meet-tile-','') : ''; if(!id || id==='__waiting') return;
     const r=el.getBoundingClientRect(); if(r.width<2||r.height<2) return;
-    let uid, local=false, name='', muted=false;
+    let uid, local=false, name='', muted=false, screen=false;
     if(id==='__local'){ uid=(ME&&ME.id)||''; local=true; name=(ME&&ME.name)||'You'; muted=!meetMic; }
-    else { uid=meetPeerUids.get(id)||''; name=meetNames.get(id)||'Guest'; muted=!!meetMuted.get(id); }
+    else { uid=meetPeerUids.get(id)||''; name=meetNames.get(id)||'Guest'; muted=!!meetMuted.get(id); screen=meetSharers.has(id); } // sharer's tile → render their screen, not camera
     if(!uid) return;
-    tiles.push({ uid, local, name, muted, x:r.left, y:r.top, w:r.width, h:r.height });
+    tiles.push({ uid, local, name, muted, screen, x:r.left, y:r.top, w:r.width, h:r.height });
   });
   try{ NC.syncVideoTiles({ tiles }); }catch(_){}
 }