kernel: microcode in every initramfs through mkinitcpio's microcode hook (issue 1977)

Declares amd-ucode and intel-ucode, the drop-in /etc/mkinitcpio.conf.d/mesh-microcode.conf, the
initramfs script and mesh-kernel-initramfs.service; kernel_boot answers the running revision and
whether the images were built with the drop-in. Tests: 1977/AC1-AC5.

Builds: L1, L2, L3, L4, L5 (issue 1977 note 2)

modules/kernel/cmd/kernel-tools/main.go

@@ -51,7 +51,8 @@ func tools(m *Machine) []stdio.Tool {
 			Description: "How this machine boots and whether the fallback kernel is on its menu (novox/hq ADR 0508 §9): the loader that booted it " +
 				"(systemd-boot, read from the EFI variable it sets, grub, or none), the menu's entries, the kernels in /boot, the entry " +
 				"the machine booted (systemd-boot) or the kernel image it booted (grub), whether the fallback kernel linux-lts is on " +
-				"the menu with its kernel in /boot, and the room free on /boot in KiB (the fallback kernel needs about 72 MB). " +
+				"the menu with its kernel in /boot, and the room free on /boot in KiB (the fallback kernel needs about 72 MB), the microcode revision the CPU runs " +
+				"(/proc/cpuinfo) and whether the initramfs images were built with the microcode drop-in (novox/hq issue 1977). " +
 				"Replaces ls /boot, bootctl list, reading grub.cfg and df /boot. (r)",
 			Input: schema(map[string]any{}),
 			Run:   func(args map[string]any) (any, error) { return m.Boot() },