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

themes/palettes/catppuccin/colors.toml

@@ -0,0 +1,23 @@
+accent = "#89b4fa"
+cursor = "#f5e0dc"
+foreground = "#cdd6f4"
+background = "#1e1e2e"
+selection_foreground = "#1e1e2e"
+selection_background = "#f5e0dc"
+
+color0 = "#45475a"
+color1 = "#f38ba8"
+color2 = "#a6e3a1"
+color3 = "#f9e2af"
+color4 = "#89b4fa"
+color5 = "#f5c2e7"
+color6 = "#94e2d5"
+color7 = "#bac2de"
+color8 = "#585b70"
+color9 = "#f38ba8"
+color10 = "#a6e3a1"
+color11 = "#f9e2af"
+color12 = "#89b4fa"
+color13 = "#f5c2e7"
+color14 = "#94e2d5"
+color15 = "#a6adc8"