Make BOS a complete, bootable, themed desktop OS

Install/boot reliability:
- Use native Calamares initcpiocfg/initcpio + explicit grub-install (nvram +
  --removable) in post-install; drop the flaky native bootloader/grubcfg modules.
- mount.conf: bind /proc /sys /dev (devtmpfs) /run + efivars into the chroot.
- bos-copy-kernel: stage kernel + write a stock mkinitcpio preset (replace the
  archiso preset). Per-service systemctl enable (fixes NetworkManager et al.
  silently not enabling due to the all-or-nothing grub-btrfs.path name).

System completeness:
- greetd + tuigreet graphical login; installed pacman.conf + working mirrorlist;
  base CLI tools (nano, micro, vim, htop, …); amd/intel-ucode; tlp + hypridle
  power management; systemd-timesyncd, fstrim.timer; wpa_supplicant wifi; Zen
  browser (republished to the [Breadway] repo).

Desktop + theming:
- Native Lua Hyprland config (hyprland.lua) with curated standard binds; kitty
  (blur) replaces foot; awww wallpaper + pywal palette (tamed to a black base
  with warm accents); GTK dark mode.
- Plymouth boot splash (bos theme: logo + spinner + status) via plymouthcfg.
- Varela Round font; Calamares bread-palette sidebar (logo/black-region polish
  still pending).

iso/airootfs/etc/calamares/settings.conf

@@ -29,8 +29,21 @@ sequence:
     - networkcfg
     - hwclock
     - packages
+    # archiso strips the kernel from the squashfs; stage it, drop the archiso
+    # initramfs config, and write a stock mkinitcpio preset before initcpio runs.
     - shellprocess@kernel
-    - bootloader
+    # plymouthcfg sets the boot-splash theme and flags plymouth in use, so
+    # initcpiocfg adds the plymouth hook to the initramfs that initcpio builds.
+    - plymouthcfg
+    # Native initramfs generation (works reliably here). The native `bootloader`
+    # and `grubcfg` modules do NOT — in this archiso layout they leave the ESP
+    # empty and abort the install, so GRUB is installed explicitly in
+    # post-install.sh instead (grub-install --removable + NVRAM + grub-mkconfig,
+    # the sequence verified to produce a bootable system).
+    - initcpiocfg
+    - initcpio
+    # BOS finalization: GRUB install + cleanup + snapper + services + dotfiles.
+    # All fast, and runs after initcpio so /boot has the kernel + initramfs.
     - shellprocess
     - umount
   - show: