v0.5.21: plymouth.enable=0 — text boot like onyx, plymouth pkg kept

User wants onyx-style boot: pure text scroll → LUKS prompt → text scroll
→ SDDM. No fedora splash, no plymouth UI.

Solution: keep plymouth PACKAGE installed (Fedora's dracut module
ships LUKS-prompt machinery via plymouth), but disable plymouthd at
runtime via kernel cmdline `plymouth.enable=0`.

Effect:
- plymouthd starts → reads cmdline → exits
- systemd-ask-password sees no plymouth daemon → falls back to
  systemd-tty-ask-password-agent on /dev/console
- LUKS prompt rendered as text "Please enter passphrase for /dev/dm-0: "
- All kernel/systemd messages visible
- SDDM still launches at graphical.target (real install)

Applied to both:
- LIVE ks bootloader --append (so live boot text-mode + installer
  visible on tty1, no splash hiding it)
- Generated install ks bootloader --append (so installed system
  text-boots with LUKS prompt)

v0.6 will rebrand plymouth theme + re-enable for branded splash. For
v0.5.0 ship: minimal/text aesthetic matches user's onyx daily driver.

kickstart/veilor-os.ks

@@ -51,7 +51,7 @@ user --name=admin --groups=wheel --gecos="veilor admin" --password="" --plaintex
 # Note: init_on_alloc/init_on_free removed from default live cmdline —
 # they zero every memory page at boot which 5x'd KVM live boot time.
 # Re-enable per-install via veilor-firstboot.service for production.
-bootloader --location=mbr --append="lockdown=integrity slab_nomerge randomize_kstack_offset=on vsyscall=none"
+bootloader --location=mbr --append="lockdown=integrity slab_nomerge randomize_kstack_offset=on vsyscall=none plymouth.enable=0"
 
 # ── Live ISO partitioning (flat — for live rootfs build only) ──
 # NOTE: This is the *live* image kickstart. Final installed system uses

overlay/usr/local/bin/veilor-installer

@@ -377,7 +377,7 @@ __SSHKEY_DIRECTIVE__
 
 # Full hardening cmdline (installed system, not live):
 # --location=none: anaconda auto-places bootloader (UEFI grub2-efi or BIOS).
-bootloader --append="lockdown=integrity slab_nomerge init_on_alloc=1 init_on_free=1 randomize_kstack_offset=on vsyscall=none"
+bootloader --append="lockdown=integrity slab_nomerge init_on_alloc=1 init_on_free=1 randomize_kstack_offset=on vsyscall=none plymouth.enable=0"
 
 # Disk: zero, LUKS2 (argon2id), btrfs subvolumes (no LVM intermediary).
 # Native btrfs-on-LUKS matches Fedora KDE Spin defaults; LVM+btrfs combo