iso: fix packages.x86_64 (no inline comments; gstreamer-vaapi -> gst-plugin-va)

Inline comments after a package name broke kitty/flatpak (became invalid
names with trailing whitespace). gstreamer-vaapi was removed from Arch.
calamares is AUR-only -> commented pending a [tanin] rebuild decision.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

iso/build-profile/syslinux/archiso_tail.cfg

@@ -0,0 +1,35 @@
+LABEL existing
+TEXT HELP
+Boot an existing operating system.
+Press TAB to edit the disk and partition number to boot.
+ENDTEXT
+MENU LABEL Boot existing OS
+COM32 chain.c32
+APPEND hd0 0
+
+# https://www.memtest.org/
+LABEL memtest
+MENU LABEL Run Memtest86+ (RAM test)
+LINUX /boot/memtest86+/memtest
+
+# https://wiki.syslinux.org/wiki/index.php/Hdt_(Hardware_Detection_Tool)
+LABEL hdt
+MENU LABEL Hardware Information (HDT)
+COM32 hdt.c32
+APPEND modules_alias=hdt/modalias.gz pciids=hdt/pciids.gz
+
+LABEL reboot
+TEXT HELP
+Reboot computer.
+The computer's firmware must support APM.
+ENDTEXT
+MENU LABEL Reboot
+COM32 reboot.c32
+
+LABEL poweroff
+TEXT HELP
+Power off computer.
+The computer's firmware must support APM.
+ENDTEXT
+MENU LABEL Power Off
+COM32 poweroff.c32