feat(iso): make toram optional, add 'load to RAM' boot menu entry

Default boot no longer loads ISO to RAM (slow on BMC virtual media).
Separate menu entry added for toram in both GRUB and isolinux.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

iso/builder/config/bootloaders/grub-pc/grub.cfg

@@ -14,6 +14,11 @@ menuentry "EASY-BEE" {
     initrd  @INITRD_LIVE@
 }
 
+menuentry "EASY-BEE (load to RAM)" {
+    linux   @KERNEL_LIVE@ @APPEND_LIVE@ toram bee.nvidia.mode=normal
+    initrd  @INITRD_LIVE@
+}
+
 menuentry "EASY-BEE (NVIDIA GSP=off)" {
     linux   @KERNEL_LIVE@ @APPEND_LIVE@ bee.nvidia.mode=gsp-off
     initrd  @INITRD_LIVE@