refactor: major architectural restructure for theme-centric organization

Theme System:
- Move all theme app configs to apps/ subdirectory (20 themes)
- Add theme-loader.nix for dynamic theme config deployment
- Simplify stylix.nix to focus on base theming only

Override System:
- Add overrides.nix for file-based config overrides
- Add behavior-configs.nix for non-visual configuration
- Split hypr/nomarchy.conf into behavior vs visual sections

Module Improvements:
- Add lib.mkDefault to all customizable settings
- Add modules/lib/ with shared utilities and state schema
- Update all home and system modules for downstream overridability

Installer:
- New minimal TTY installer (installer/install.sh)
- Golden path: BTRFS + LUKS2 (disko-golden.nix)
- New installer-iso.nix for TTY-only installation
- Keep graphical installer as installerIsoGraphical option

Cleanup:
- Remove obsolete install.sh, disko-ext4.nix, install-nomarchy.sh
- Update live-iso.nix references
- Add .claude/ to .gitignore for local IDE settings

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

hosts/live-iso.nix

@@ -8,7 +8,7 @@
     (pkgs.makeDesktopItem {
       name = "install-nomarchy";
       desktopName = "Install Nomarchy";
-      exec = "alacritty -e sudo /etc/install-nomarchy.sh";
+      exec = "alacritty -e sudo /etc/install.sh";
       terminal = false;
       categories = [ "System" ];
     })
@@ -17,17 +17,13 @@
   # Ensure the live environment user has the necessary groups for graphical acceleration and audio
   users.users.nixos.extraGroups = [ "wheel" "video" "render" "audio" "networkmanager" ];
 
-  environment.etc."install-nomarchy.sh" = {
-    source = ../installer/install-nomarchy.sh;
+  environment.etc."install.sh" = {
+    source = ../installer/install.sh;
     mode = "0755";
   };
 
-  environment.etc."disko-ext4.nix" = {
-    source = ../installer/disko-ext4.nix;
-  };
-
-  environment.etc."disko-btrfs-luks.nix" = {
-    source = ../installer/disko-btrfs-luks.nix;
+  environment.etc."disko-golden.nix" = {
+    source = ../installer/disko-golden.nix;
   };
 
   environment.etc."nomarchy".source = inputs.self;