ci cross-platform fix: make system_info disk usage helper windows-safe with build tags

pkg/tools/system_disk_unix.go

@@ -0,0 +1,22 @@
+//go:build !windows
+
+package tools
+
+import "fmt"
+import "syscall"
+
+func diskUsageRoot() string {
+	var stat syscall.Statfs_t
+	if err := syscall.Statfs("/", &stat); err != nil {
+		return ""
+	}
+	bsize := uint64(stat.Bsize)
+	total := stat.Blocks * bsize
+	free := stat.Bfree * bsize
+	used := total - free
+	if total == 0 {
+		return ""
+	}
+	return fmt.Sprintf("Disk (/): Used %.2f GB / Total %.2f GB (%.2f%%)\n",
+		float64(used)/1024/1024/1024, float64(total)/1024/1024/1024, float64(used)/float64(total)*100)
+}