refactor: Move recipe generator to cook/ directory and fix flattening bugs

- Move recipe-generator/ to cook/ for cleaner structure

- Fix ksflatten-relative path conversion to handle all %include paths

- Fix validation exit code to only fail on actual errors

- All recipes now generate and flatten successfully via make all

cook/dishes/install_virtual_server_43.cfg

@@ -0,0 +1,55 @@
+# Generated by pykickstart v3.69
+#version=DEVEL
+# Use text mode install
+text
+# Firewall configuration
+firewall --enabled
+# Run the Setup Agent on first boot
+firstboot --reconfig
+# Keyboard layouts
+keyboard --xlayouts='ch (fr)'
+# System language
+lang en_US.UTF-8
+# Network information
+network  --bootproto=dhcp --device=link --hostname=phyllome-alpha --activate
+# Shutdown after installation
+shutdown
+repo --name="fedora" --mirrorlist=https://mirrors.fedoraproject.org/mirrorlist?repo=fedora-43&arch=x86_64
+repo --name="updates" --mirrorlist=https://mirrors.fedoraproject.org/mirrorlist?repo=updates-released-f43&arch=x86_64
+#Root password
+rootpw --lock
+# SELinux configuration
+selinux --enforcing
+# System services
+services --enabled="NetworkManager,systemd-resolved"
+# System timezone
+timezone Europe/Zurich --utc
+# Use network installation
+url --mirrorlist="https://mirrors.fedoraproject.org/mirrorlist?repo=fedora-43&arch=x86_64"
+# System bootloader configuration
+bootloader --location=mbr --timeout=1
+# Clear the Master Boot Record
+zerombr
+# Partition clearing information
+clearpart --all --initlabel
+# Disk partitioning information
+part /boot/efi --fstype="efi" --size=512 --fsoptions="umask=0077,shortname=winnt" --label="efi"
+part /boot --fstype="ext4" --size=2048 --label="boot"
+part / --fstype="ext4" --grow --label="root" --mkfsoptions="-O encrypt,fast_commit"
+
+%packages --exclude-weakdeps
+@core
+curl
+fedora-remix-logos
+generic-logos
+generic-release
+generic-release-common
+generic-release-notes
+initial-setup
+libusb
+nano
+pciutils
+usbutils
+wget
+
+%end