Fix PAL review findings: documentation accuracy and code quality

- Update CLAUDE.md with complete kernel parameters including boot=netboot
- Remove duplicate wget/curl package declarations in build-image.sh
- Check unsquashfs in both /usr/bin and /usr/sbin in verify-image.sh
- Use consistent $quiet variable expansion in netboot hook functions

All issues identified in zen-opus pre-commit review are now resolved.

initramfs/scripts/netboot

@@ -11,7 +11,7 @@ TMPFS_MOUNT=/mnt
 netboot_top()
 {
 	if [ "${netboot_top_used}" != "yes" ]; then
-		[ "${quiet?}" != "y" ] && log_begin_msg "Running /scripts/netboot-top"
+		[ "$quiet" != "y" ] && log_begin_msg "Running /scripts/netboot-top"
 		run_scripts /scripts/netboot-top
 		[ "$quiet" != "y" ] && log_end_msg
 	fi
@@ -21,7 +21,7 @@ netboot_top()
 netboot_premount()
 {
 	if [ "${netboot_premount_used}" != "yes" ]; then
-		[ "${quiet?}" != "y" ] && log_begin_msg "Running /scripts/netboot-premount"
+		[ "$quiet" != "y" ] && log_begin_msg "Running /scripts/netboot-premount"
 		run_scripts /scripts/netboot-premount
 		[ "$quiet" != "y" ] && log_end_msg
 	fi
@@ -31,7 +31,7 @@ netboot_premount()
 netboot_bottom()
 {
 	if [ "${netboot_premount_used}" = "yes" ] || [ "${netboot_top_used}" = "yes" ]; then
-		[ "${quiet?}" != "y" ] && log_begin_msg "Running /scripts/netboot-bottom"
+		[ "$quiet" != "y" ] && log_begin_msg "Running /scripts/netboot-bottom"
 		run_scripts /scripts/netboot-bottom
 		[ "$quiet" != "y" ] && log_end_msg
 	fi