Enhance boot configuration for custom ISO with USB delay and filesystem support

- Added isofs module to boot configurations for both UEFI (GRUB) and Legacy BIOS (Syslinux) to enable ISO9660 filesystem support.
- Updated boot parameters to improve USB delay and debugging capabilities for better hardware compatibility.

image-recipe/build-overlay-iso.sh

@@ -279,22 +279,25 @@ chmod +x "$ISO_CUSTOM/archipelago/setup-archipelago.sh"
 echo "⚙️  Configuring boot..."
 
 # Modify boot configs to add USB delay for better hardware compatibility
-# Keep Alpine's boot logic intact, just add timing parameters
+# Keep Alpine's boot logic intact, just add timing parameters and better debugging
 # HP ProDesk likely boots UEFI (GRUB), so we need to modify both configs
+# CRITICAL: Add isofs module so Alpine can mount the ISO9660 filesystem on USB!
+# CRITICAL: Add pkgs parameter to explicitly install base system packages
 
 if [ -f "$ISO_CUSTOM/boot/grub/grub.cfg" ]; then
-    # UEFI boot (GRUB) - add usbdelay and debug
+    # UEFI boot (GRUB) - add isofs module for ISO9660 filesystem support
     sed -i.bak \
         -e 's/Alpine Linux/Archipelago Bitcoin Node OS/g' \
-        -e 's/quiet/usbdelay=5 debug_init/' \
+        -e 's/modules=loop,squashfs,sd-mod,usb-storage quiet/modules=loop,squashfs,sd-mod,usb-storage,isofs,iso9660 usbdelay=10/' \
         "$ISO_CUSTOM/boot/grub/grub.cfg"
 fi
 
 if [ -f "$ISO_CUSTOM/boot/syslinux/syslinux.cfg" ]; then
-    # Legacy BIOS boot (Syslinux) - add usbdelay and debug
+    # Legacy BIOS boot (Syslinux) - add isofs module for ISO9660 filesystem support
     sed -i.bak \
         -e 's/Alpine Linux/Archipelago Bitcoin Node OS/g' \
-        -e 's/quiet/usbdelay=5 debug_init/' \
+        -e 's/quiet/usbdelay=10/' \
+        -e 's/modules=loop,squashfs,sd-mod,usb-storage/modules=loop,squashfs,sd-mod,usb-storage,isofs,iso9660/' \
         "$ISO_CUSTOM/boot/syslinux/syslinux.cfg"
 fi