Add zsh and linux-firmware to rootfs packages

users.conf sets every new user's default shell to zsh regardless of
which desktop environment they choose, but zsh was never actually
guaranteed to be installed — this locks users out at their very first
login (pam_shells.so rejects the shell before the password is even
checked). Fixed by ensuring zsh is present for every install, not
just KDE.

Also adds linux-firmware, without which GPU/wifi/etc. drivers can
fail to initialize entirely on first boot.

iso-profiles/antergos/profile.yaml

@@ -61,6 +61,16 @@ rootfs:
     - kwin-zones
     - oh-my-posh-bin
     - pacseek
+    # Fixes a real lockout bug: users.conf sets every new user's shell to
+    # zsh regardless of which desktop they choose, but zsh was never
+    # actually guaranteed to be installed. This applies to every desktop
+    # choice, not just KDE, so it belongs here rather than in any one
+    # desktop's package block.
+    - zsh
+    # Without this, GPU/wifi/etc. drivers can fail to initialize at all
+    # on first boot — worse than anything a post-install tool can fix,
+    # since the person may not even get a usable display to fix it with.
+    - linux-firmware
   packages-init:
     dinit:
       - pipewire-dinit