chore: refactor pxe templates to jinja templates rendered by askama

examples/okd_pxe/templates/fallback.ipxe.j2

@@ -0,0 +1,40 @@
+#!ipxe
+
+# =================================================================
+#  Harmony Discovery Agent - Default Boot Script (default.ipxe)
+# =================================================================
+#
+# This script boots the CentOS Stream live environment for the
+# purpose of hardware inventory. It loads the kernel and initramfs
+# directly and passes a Kickstart URL for full automation.
+#
+
+# --- Configuration
+# Set the base URL for where the CentOS kernel/initrd are hosted.
+set os_base_url http://{{gateway_ip}}:8080/os/centos-stream-9
+# Set the URL for the Kickstart file.
+set ks_url http://{{ gateway_ip }}:8080/{{ kickstart_filename }}
+
+# --- Boot Process
+echo "Harmony: Starting automated node discovery..."
+echo "Fetching kernel from ${os_base_url}/vmlinuz..."
+kernel ${os_base_url}/vmlinuz
+
+echo "Fetching initramfs from ${os_base_url}/initrd.img..."
+initrd ${os_base_url}/initrd.img
+
+echo "Configuring kernel boot arguments..."
+# Kernel Arguments Explained:
+# - initrd=initrd.img:      Specifies the initial ramdisk to use.
+# - inst.stage2:            Points to the OS source. For a live boot, the base URL is sufficient.
+# - inst.ks:                CRITICAL: Points to our Kickstart file for automation.
+# - ip=dhcp:                Ensures the live environment configures its network.
+# - console=...:            Provides boot output on both serial and graphical consoles for debugging.
+imgargs vmlinuz initrd=initrd.img inst.stage2=${os_base_url} inst.ks=${ks_url} ip=dhcp console=ttyS0,115200 console=tty1
+
+echo "Booting into CentOS Stream 9 live environment..."
+boot || goto failed
+
+:failed
+echo "Boot failed. Dropping to iPXE shell."
+shell