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>

modules/lib/state-schema.nix

@@ -0,0 +1,66 @@
+# Nomarchy State Schema
+# Defines the complete state shape with defaults for both home and system state
+{ lib }:
+
+{
+  # Home state defaults (user preferences)
+  home = {
+    # Theme and appearance
+    theme = "nord";
+    wallpaper = "";
+    font = "JetBrainsMono Nerd Font";
+    nightlightTemperature = 4000;
+
+    # Feature toggles
+    suspend = true;
+    screensaver = true;
+    idle = true;
+    nightlight = false;
+    waybar = true;
+    skipVsCodeTheme = false;
+
+    # Hyprland window manager settings
+    hyprland = {
+      gaps_in = 5;
+      gaps_out = 10;
+      border_size = 2;
+    };
+  };
+
+  # System state defaults (system-level configuration)
+  system = {
+    # Theme (can differ from home for system-level theming)
+    theme = "nord";
+
+    # Timezone
+    timezone = "UTC";
+
+    # DNS configuration
+    dns = "DHCP";  # Options: "DHCP", "Cloudflare", "Google", "Custom"
+    customDns = [];
+
+    # Wi-Fi settings
+    wifi = {
+      powersave = true;
+    };
+
+    # Optional features
+    features = {
+      fingerprint = false;
+      fido2 = false;
+      hybridGPU = false;
+      makima = false;
+    };
+  };
+
+  # Get a value from state with fallback to default
+  getWithDefault = state: path: default:
+    let
+      pathList = lib.splitString "." path;
+      getValue = obj: remaining:
+        if remaining == [] then obj
+        else if builtins.isAttrs obj && builtins.hasAttr (builtins.head remaining) obj
+        then getValue obj.${builtins.head remaining} (builtins.tail remaining)
+        else default;
+    in getValue state pathList;
+}