feat: expose drive labels to userspace, render in Files

programs/include/libc/montauk.h

@@ -92,6 +92,7 @@ extern "C" {
 #define MTK_SYS_FMKDIR          78
 #define MTK_SYS_FRENAME         94
 #define MTK_SYS_DRIVELIST       79
+#define MTK_SYS_DRIVELABEL      124
 #define MTK_SYS_AUDIOOPEN       80
 #define MTK_SYS_AUDIOCLOSE      81
 #define MTK_SYS_AUDIOWRITE      82