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

core/home/config/imv/config

@@ -0,0 +1,13 @@
+[binds]
+
+# Print the current image file
+<Ctrl+p> = exec lp "$imv_current_file"
+
+# Delete the current image and quit the viewer
+<Ctrl+x> = exec rm "$imv_current_file"; quit
+
+# Delete the current image and move to the next one
+<Ctrl+Shift+X> = exec rm "$imv_current_file"; close
+
+# Rotate the currently open image by 90 degrees
+<Ctrl+r> = exec mogrify -rotate 90 "$imv_current_file"