fix ring publishj

Author: archandatta

server/lib/events/capturesession.go

@@ -33,8 +33,9 @@ func (s *CaptureSession) Start(captureSessionID string) {
 
 // Publish wraps ev in an Envelope, truncates if needed, then writes to
 // FileWriter (durable) before RingBuffer (in-memory fan-out).
-// The mutex is held only for envelope construction; file I/O and ring publish
-// happen outside the lock (both are internally synchronized).
+// The mutex is held through ring publish to preserve seq ordering for readers.
+// File I/O happens outside the lock since FileWriter has its own mutex and
+// JSONL lines are independent (no ordering requirement).
 func (s *CaptureSession) Publish(ev Event) {
 	if ev.Ts == 0 {
 		ev.Ts = time.Now().UnixMilli()
@@ -50,14 +51,14 @@ func (s *CaptureSession) Publish(ev Event) {
 		Event:            ev,
 	}
 	env, data := truncateIfNeeded(env)
+	s.ring.Publish(env)
 	s.mu.Unlock()
 
 	if data == nil {
 		slog.Error("capture_session: marshal failed, skipping file write", "seq", env.Seq, "category", env.Event.Category)
 	} else if err := s.files.Write(env, data); err != nil {
 		slog.Error("capture_session: file write failed", "seq", env.Seq, "category", env.Event.Category, "err", err)
 	}
-	s.ring.Publish(env)
 }
 
 // NewReader returns a Reader positioned at the start of the ring buffer.