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

features/apps/kitty/config/kitty.conf

@@ -0,0 +1,30 @@
+include ~/.config/nomarchy/current/theme/kitty.conf
+
+# Font
+font_family JetBrainsMono Nerd Font
+bold_italic_font auto
+font_size        9.0
+
+# Window
+window_padding_width 14
+hide_window_decorations yes
+confirm_os_window_close 0
+
+# Keybindings
+map ctrl+insert copy_to_clipboard
+map shift+insert paste_from_clipboard
+
+# Allow remote access
+allow_remote_control yes
+
+# Aesthetics
+cursor_shape block
+cursor_blink_interval 0
+shell_integration no-cursor
+enable_audio_bell no
+
+# Minimal Tab bar styling
+tab_bar_edge                bottom
+tab_bar_style               powerline
+tab_powerline_style         slanted
+tab_title_template          {title}{' :{}:'.format(num_windows) if num_windows > 1 else ''}