fix(sync): send LastSeenServerSeq from CLI push, report conflicts

cmd/verstak/main.go

@@ -672,6 +672,11 @@ func runSyncPush(args []string) {
 		return
 	}
 
+	_, _, lastSeq, _, _ := syncSvc.GetState()
+	for i := range unpushed {
+		unpushed[i].LastSeenServerSeq = lastSeq
+	}
+
 	result, err := client.Push(unpushed)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "Push failed: %v\n", err)
@@ -684,6 +689,9 @@ func runSyncPush(args []string) {
 	}
 
 	fmt.Printf("Pushed %d ops, accepted %d\n", len(unpushed), len(result.Accepted))
+	if len(result.Conflicts) > 0 {
+		fmt.Printf("WARNING: %d conflict(s) detected\n", len(result.Conflicts))
+	}
 }
 
 func runSyncPull(args []string) {