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/skel/.cache/wal/colors.json

@@ -0,0 +1,28 @@
+{
+    "wallpaper": "/usr/share/backgrounds/bos/bread-background.png",
+    "alpha": "100",
+
+    "special": {
+        "background": "#0c0c0c",
+        "foreground": "#e8e8e8",
+        "cursor": "#eab672"
+    },
+    "colors": {
+        "color0": "#1a1a1a",
+        "color1": "#b98749",
+        "color2": "#cd9450",
+        "color3": "#e3a85c",
+        "color4": "#eab672",
+        "color5": "#f6c477",
+        "color6": "#eabe82",
+        "color7": "#d8d8d8",
+        "color8": "#3a3a3a",
+        "color9": "#b98749",
+        "color10": "#cd9450",
+        "color11": "#e3a85c",
+        "color12": "#eab672",
+        "color13": "#f6c477",
+        "color14": "#eabe82",
+        "color15": "#f5f5f5"
+    }
+}