Fix critical boot issues: partition detection, GRUB config, and file copying

- Fixed wait_for_partitions to check both EFI (p1) and root (p2) partitions
- Fixed GRUB configuration to use actual root filesystem UUID instead of placeholder
- Fixed GRUB partition reference from (hd0,gpt1) to (hd0,gpt2) for root partition
- Fixed GRUB EFI binary path to use correct monolithic grubx64.efi
- Successfully copying rootfs files (278MB images with full filesystem)
- GRUB EFI binary properly installed to EFI partition

Still debugging actual Linux boot - system shows SeaBIOS and 'Booting from Hard Disk' but doesn't boot into kernel

test-rootfs/tmp/initramfs/bootc

@@ -0,0 +1,28 @@
+#!/bin/bash
+# Bootc binary - placeholder implementation
+# In a real implementation, this would be the actual bootc binary
+
+set -euo pipefail
+
+echo "Bootc: Starting container boot process..."
+
+# Read configuration
+CONFIG_FILE="/etc/bootc.conf"
+if [[ -f "$CONFIG_FILE" ]]; then
+    source "$CONFIG_FILE"
+fi
+
+# Set up composefs
+if [[ "${composefs_enabled:-yes}" == "yes" ]]; then
+    echo "Bootc: Setting up composefs..."
+    # This would use ostree-ext-container in a real implementation
+    echo "Bootc: Composefs setup complete"
+fi
+
+# Mount the container filesystem
+echo "Bootc: Mounting container filesystem..."
+# This would mount the container as the root filesystem
+
+# Execute the real init
+echo "Bootc: Executing real init..."
+exec /sbin/systemd

test-rootfs/tmp/initramfs/init

@@ -0,0 +1,2 @@
+#!/bin/sh
+exec /bootc