refactor: consolidate app configurations and utility scripts

- Move 32+ app-specific scripts from features/apps/scripts/ to features/scripts/utils/ for centralized packaging.
- Create individual Nix modules for orphaned app configurations (btop, kitty, tmux, etc.) in features/apps/ using xdg.configFile.
- Fix broken paths in core/system/makima.nix and features/apps/vscode.nix.
- Update VSCode configuration to use the modern 'profiles.default.userSettings' API, resolving deprecation warnings.
- Merge duplicate 'nomarchy-launch-walker' scripts into a single robust utility.
- Remove stale root 'config/' directory.
- Update README.md and docs/creating-themes.md to reflect the new architecture and keybindings.
- Ensure all modules are correctly imported and verified via nix flake check.

core/default.nix

@@ -1,22 +1,5 @@
-{ config, lib, pkgs, ... }:
+{ ... }:
 
 {
-  imports = [
-    ./system/options.nix
-    ./system/state.nix
-    ./system/systemd.nix
-    ./system/virtualization.nix
-    ./system/fonts.nix
-    ../themes/engine/plymouth.nix
-    ../themes/engine/sddm.nix
-    ./system/hardware.nix
-    ./system/audio.nix
-    ./system/bluetooth.nix
-    ./system/network.nix
-    ../features/apps/browser.nix
-    ./system/impermanence.nix
-    ../features/apps/makima.nix
-  ];
-
-  time.timeZone = lib.mkDefault config.nomarchy.system.timezone;
+  imports = [ ./system ];
 }