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.

features/default.nix

@@ -15,28 +15,30 @@ in
   imports = [
     inputs.nix-colors.homeManagerModules.default
     inputs.walker.homeManagerModules.default
+    ../core/home
     ../themes/engine/stylix-compat.nix
-    ../core/home/options.nix
-    ../core/home/state.nix
-    ../core/home/overrides.nix
-    ../core/home/behavior.nix
     ../themes/engine/loader.nix
     ../themes/engine/files.nix
-    ../core/home/fonts.nix
+    ../themes/engine/stylix.nix
+    ../themes/engine/switcher.nix
     ./apps/alacritty/default.nix
+    ./apps/btop/default.nix
+    ./apps/chromium/default.nix
+    ./apps/elephant/default.nix
+    ./apps/ghostty/default.nix
+    ./apps/kitty/default.nix
+    ./apps/lazygit/default.nix
+    ./apps/opencode/default.nix
+    ./apps/tmux/default.nix
+    ./apps/vscode.nix
+    ./apps/walker.nix
+    ./apps/swayosd.nix
     ./desktop/nightlight.nix
     ./desktop/idle.nix
-    ../themes/engine/stylix.nix
     ./desktop/hyprland/default.nix
     ./desktop/waybar/default.nix
-    ./apps/walker.nix
-    ../themes/engine/switcher.nix
     ./scripts/default.nix
-    ../core/home/configs.nix
-    ./apps/swayosd.nix
-    ../core/home/security.nix
     ./scripts/battery-monitor.nix
-    ../core/home/bash.nix
   ];