feat(machine): add OS and kernel version information to machine info, show in 'machine ls'

internal/machine/osinfo/osinfo_linux.go

@@ -0,0 +1,12 @@
+package osinfo
+
+import "golang.org/x/sys/unix"
+
+// KernelVersion returns the running Linux kernel release, e.g. "6.8.0-31-generic".
+func KernelVersion() string {
+	var un unix.Utsname
+	if err := unix.Uname(&un); err != nil {
+		return ""
+	}
+	return unix.ByteSliceToString(un.Release[:])
+}