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/scripts/nomarchy-launch-browser

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+# Launch the default browser as determined by xdg-settings.
+# Automatically converts --private into the correct flag for the given browser.
+
+default_browser=$(xdg-settings get default-web-browser)
+browser_exec=$(sed -n 's/^Exec=\([^ ]*\).*/\1/p' {~/.local,~/.nix-profile,/usr}/share/applications/$default_browser 2>/dev/null | head -1)
+
+if $browser_exec --help | grep -q MOZ_LOG; then
+  private_flag="--private-window"
+elif [[ $browser_exec =~ edge ]]; then
+  private_flag="--inprivate"
+else
+  private_flag="--incognito"
+fi
+
+exec setsid uwsm-app -- "$browser_exec" "${@/--private/$private_flag}"