fix: screenshare codec fallback, native FPS, and connection info

- Gaming mode uses H.264 primary (hardware NVENC encoding, zero CPU
  impact on games). Text mode uses VP9 primary with H.264 backup
  and SIMULCAST policy for Safari compatibility.
- Fix native mode starting at 30fps by decoupling frameRate constraint
  from resolution constraint in both screenShare.ts overdrive and
  useLiveKit.ts updateActiveTracks.
- Filter paused backup codec tracks in Connection Info stats so dead
  0kbps entries don't show alongside active codec tracks.

packages/web/src/hooks/useLiveKit.ts

@@ -612,9 +612,12 @@ export function useLiveKit() {
         if (screenPub?.videoTrack) {
           const mediaTrack = getMediaStreamTrack(screenPub.videoTrack);
           if (mediaTrack) {
-            // Skip resolution constraints for native mode — capture is already at native dims
             if (opts.capture.width > 0 && opts.capture.height > 0) {
-              await mediaTrack.applyConstraints({ width: { ideal: opts.capture.width }, height: { ideal: opts.capture.height }, frameRate: { ideal: opts.capture.frameRate } });
+              // Standard mode: apply resolution + frameRate together
+              await mediaTrack.applyConstraints({ width: { ideal: opts.capture.width }, height: { ideal: opts.capture.height }, frameRate: { ideal: opts.capture.frameRate, min: 15 } });
+            } else {
+              // Native mode: apply frameRate only — never pass 0 to width/height
+              await mediaTrack.applyConstraints({ frameRate: { ideal: opts.capture.frameRate, min: 15 } });
             }
             mediaTrack.contentHint = opts.contentHint;
           }