refactor: implement component-based architecture for enhanced maintainability

- Reorganize directory structure into core/, features/, and themes/
- Colocate application Nix logic, configs, scripts, and theme overrides
- Implement 'Inversion of Control' for theming: apps now pull theme-specific layouts
- Update flake.nix and shared library paths to match the new structure
- Document the new Feature-Centric architecture in README.md

core/system/scripts/nomarchy-update

@@ -0,0 +1,38 @@
+#!/usr/bin/env bash
+
+# Nomarchy Update Script
+# 1. Updates the flake inputs in /etc/nixos
+# 2. Applies system-wide NixOS changes
+# 3. Applies user-level Home Manager changes
+
+set -e
+
+REPO_DIR="/etc/nixos"
+
+if [ ! -d "$REPO_DIR" ]; then
+    echo "Error: $REPO_DIR not found. Are you running on a Nomarchy system?"
+    exit 1
+fi
+
+echo "--- Starting Nomarchy Update ---"
+
+# 1. Update Flake Lock
+echo "Updating flake inputs..."
+sudo nix --extra-experimental-features "nix-command flakes" flake update --flake "$REPO_DIR"
+
+# 2. Rebuild System
+echo "Applying system-level updates..."
+sudo nixos-rebuild switch --flake "$REPO_DIR#default" --impure
+
+# 3. Rebuild Home Environment
+echo "Applying user-level updates..."
+home-manager switch --flake "$REPO_DIR#default" --impure
+
+# 4. Commit changes if it's a git repo
+if [ -d "$REPO_DIR/.git" ]; then
+    echo "Committing update to local history..."
+    sudo git -C "$REPO_DIR" add flake.lock
+    sudo git -C "$REPO_DIR" commit -m "chore: update system (flake.lock)" || echo "No lockfile changes to commit."
+fi
+
+echo "--- Nomarchy Update Complete ---"