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/sshd-setup.sh

@@ -0,0 +1,15 @@
+#!/bin/ash
+if [ -f /etc/ssh/ssh_host_rsa_key ]; then
+    # ensure existing file permissions
+    chown root:root /etc/ssh/ssh_host_*
+    chmod 600 /etc/ssh/ssh_host_*
+    exit 0
+fi
+
+echo "Setting up sshd"
+mkdir -p /run/sshd
+
+ssh-keygen -f /etc/ssh/ssh_host_rsa_key -N '' -t rsa
+ssh-keygen -f /etc/ssh/ssh_host_dsa_key -N '' -t dsa
+ssh-keygen -f /etc/ssh/ssh_host_ecdsa_key -N '' -t ecdsa -b 521
+ssh-keygen -f /etc/ssh/ssh_host_ed25519_key -N '' -t ed25519