fix: add Windows support for filesystem sync operations

go.mod

@@ -157,3 +157,5 @@ require (
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20251022142026-3a174f9686a8 // indirect
 	gopkg.in/natefinch/lumberjack.v2 v2.2.1 // indirect
 )
+
+replace github.com/luxfi/genesis => /Users/z/work/lux/genesis

local/network.go

@@ -17,7 +17,6 @@ import (
 	"regexp"
 	"strings"
 	"sync"
-	"syscall"
 	"time"
 
 	"github.com/luxfi/crypto/bls"
@@ -967,7 +966,7 @@ func (ln *localNetwork) pauseNode(ctx context.Context, nodeName string) error {
 	if exitCode != 0 && exitCode != -1 && exitCode != 2 && exitCode != 130 && exitCode != 143 {
 		return fmt.Errorf("node %q exited with exit code: %d", nodeName, exitCode)
 	}
-	syscall.Sync()
+	syncFilesystem()
 	node.paused = true
 	return nil
 }
@@ -1092,7 +1091,7 @@ func (ln *localNetwork) restartNode(
 		if err := ln.removeNode(ctx, nodeName); err != nil {
 			return err
 		}
-		syscall.Sync()
+		syncFilesystem()
 
 		// Wait for ports to be released (TCP TIME_WAIT)
 		// This prevents "bind: address already in use" errors

local/snapshot.go

@@ -8,7 +8,6 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
-	"syscall"
 
 	"github.com/luxfi/netrunner/api"
 	"github.com/luxfi/netrunner/network"
@@ -156,7 +155,7 @@ func (ln *localNetwork) SaveSnapshot(ctx context.Context, snapshotName string) (
 	if err := ln.stop(ctx); err != nil {
 		return "", err
 	}
-	syscall.Sync()
+	syncFilesystem()
 	// create main snapshot dirs
 	snapshotDBDir := filepath.Join(snapshotDir, defaultDBSubdir)
 	if err := os.MkdirAll(snapshotDBDir, os.ModePerm); err != nil {

local/sync_unix.go

@@ -0,0 +1,11 @@
+//go:build !windows
+// +build !windows
+
+package local
+
+import "syscall"
+
+// syncFilesystem syncs all filesystems on Unix-like systems.
+func syncFilesystem() {
+	syscall.Sync()
+}

local/sync_windows.go

@@ -0,0 +1,11 @@
+//go:build windows
+// +build windows
+
+package local
+
+// syncFilesystem is a no-op on Windows.
+// Windows doesn't have an equivalent syscall.Sync() function.
+// File handles are synced individually via FlushFileBuffers.
+func syncFilesystem() {
+	// No-op on Windows
+}