feat: Create minimal Zero-OS initramfs with console support

- Fixed build system to clone source repositories instead of downloading binaries
- Enhanced scripts/fetch-github.sh with proper git repo cloning and branch handling
- Updated scripts/compile-components.sh for RFS compilation with build-binary feature
- Added minimal firmware installation for essential network drivers (73 modules)
- Created comprehensive zinit configuration set (15 config files including getty)
- Added util-linux package for getty/agetty console support
- Optimized package selection for minimal 27MB initramfs footprint
- Successfully builds bootable vmlinuz.efi with embedded initramfs
- Confirmed working: VM boot, console login, network drivers, zinit init system

Components:
- initramfs.cpio.xz: 27MB compressed minimal Zero-OS image
- vmlinuz.efi: 35MB bootable kernel with embedded initramfs
- Complete Zero-OS toolchain: zinit, rfs, mycelium compiled from source

configs/zinit/init/cgroup.sh

@@ -0,0 +1,10 @@
+set -x
+
+mount -t tmpfs cgroup_root /sys/fs/cgroup
+
+subsys="pids cpuset cpu cpuacct blkio memory devices freezer net_cls perf_event net_prio hugetlb"
+
+for sys in $subsys; do
+    mkdir -p /sys/fs/cgroup/$sys
+    mount -t cgroup $sys -o $sys /sys/fs/cgroup/$sys/
+done