feat: Nomarchy ground-up rewrite on NixOS 26.05

Full replacement of the previous iteration, rebuilt around three ideas:

- Pure evaluation: theme-state.json lives inside the flake and is read
  via the nomarchy.stateFile option — no --impure, ever.
- All-Home-Manager theming: `nomarchy-theme-sync apply` writes the JSON
  and runs `home-manager switch`; every theme change is one atomic,
  rollbackable generation. Wallpaper (swww) is the sole runtime piece.
- Flat, downstream-first layout: modules/{nixos,home} with one
  options.nix each, exported as nixosModules/homeModules + overlay +
  flake template; system (nixos-rebuild) and desktop (home-manager
  switch) rebuild paths are fully split.

Ships 21 themes imported from the previous iteration (palettes,
wallpapers, btop themes, six whole-swap Waybar identities), Stylix for
the GTK/Qt/cursor long tail, a live ISO target with offline theme
switching, and docs/TESTING.md with the QEMU verification workflow.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

themes/nord/btop.theme

@@ -0,0 +1,89 @@
+#Bashtop theme with nord palette (https://www.nordtheme.com)
+#by Justin Zobel <justin.zobel@gmail.com>
+
+# Colors should be in 6 or 2 character hexadecimal or single spaced rgb decimal: "#RRGGBB", "#BW" or "0-255 0-255 0-255"
+# example for white: "#ffffff", "#ff" or "255 255 255".
+
+# All graphs and meters can be gradients
+# For single color graphs leave "mid" and "end" variable empty.
+# Use "start" and "end" variables for two color gradient
+# Use "start", "mid" and "end" for three color gradient
+
+# Main background, empty for terminal default, need to be empty if you want transparent background
+theme[main_bg]="#2E3440"
+
+# Main text color
+theme[main_fg]="#D8DEE9"
+
+# Title color for boxes
+theme[title]="#8FBCBB"
+
+# Highlight color for keyboard shortcuts
+theme[hi_fg]="#5E81AC"
+
+# Background color of selected item in processes box
+theme[selected_bg]="#4C566A"
+
+# Foreground color of selected item in processes box
+theme[selected_fg]="#ECEFF4"
+
+# Color of inactive/disabled text
+theme[inactive_fg]="#4C566A"
+
+# Misc colors for processes box including mini cpu graphs, details memory graph and details status text
+theme[proc_misc]="#5E81AC"
+
+# Cpu box outline color
+theme[cpu_box]="#4C566A"
+
+# Memory/disks box outline color
+theme[mem_box]="#4C566A"
+
+# Net up/down box outline color
+theme[net_box]="#4C566A"
+
+# Processes box outline color
+theme[proc_box]="#4C566A"
+
+# Box divider line and small boxes line color
+theme[div_line]="#4C566A"
+
+# Temperature graph colors
+theme[temp_start]="#81A1C1"
+theme[temp_mid]="#88C0D0"
+theme[temp_end]="#ECEFF4"
+
+# CPU graph colors
+theme[cpu_start]="#81A1C1"
+theme[cpu_mid]="#88C0D0"
+theme[cpu_end]="#ECEFF4"
+
+# Mem/Disk free meter
+theme[free_start]="#81A1C1"
+theme[free_mid]="#88C0D0"
+theme[free_end]="#ECEFF4"
+
+# Mem/Disk cached meter
+theme[cached_start]="#81A1C1"
+theme[cached_mid]="#88C0D0"
+theme[cached_end]="#ECEFF4"
+
+# Mem/Disk available meter
+theme[available_start]="#81A1C1"
+theme[available_mid]="#88C0D0"
+theme[available_end]="#ECEFF4"
+
+# Mem/Disk used meter
+theme[used_start]="#81A1C1"
+theme[used_mid]="#88C0D0"
+theme[used_end]="#ECEFF4"
+
+# Download graph colors
+theme[download_start]="#81A1C1"
+theme[download_mid]="#88C0D0"
+theme[download_end]="#ECEFF4"
+
+# Upload graph colors
+theme[upload_start]="#81A1C1"
+theme[upload_mid]="#88C0D0"
+theme[upload_end]="#ECEFF4"

themes/nord/waybar.css

@@ -0,0 +1,14 @@
+@define-color background #2e3440;
+@define-color foreground #d8dee9;
+@define-color accent #88c0d0;
+
+/* Base style for Nord */
+* {
+  font-family: JetBrainsMono Nerd Font, FontAwesome;
+  font-size: 13px;
+}
+
+window#waybar {
+  background-color: @background;
+  color: @foreground;
+}