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/ethereal/colors.toml

@@ -0,0 +1,23 @@
+accent = "#7d82d9"
+cursor = "#ffcead"
+foreground = "#ffcead"
+background = "#060B1E"
+selection_foreground = "#060B1E"
+selection_background = "#ffcead"
+
+color0 = "#060B1E"
+color1 = "#ED5B5A"
+color2 = "#92a593"
+color3 = "#E9BB4F"
+color4 = "#7d82d9"
+color5 = "#c89dc1"
+color6 = "#a3bfd1"
+color7 = "#F99957"
+color8 = "#6d7db6"
+color9 = "#faaaa9"
+color10 = "#c4cfc4"
+color11 = "#f7dc9c"
+color12 = "#c2c4f0"
+color13 = "#ead7e7"
+color14 = "#dfeaf0"
+color15 = "#ffcead"