Scaffold BOS repo: dotfiles, ISO profile, and bos-settings GTK4 app

Implements all four components from the BOS spec:
- dotfiles/: default Hyprland, bread, breadbox, breadcrumbs configs
- iso/: archiso profiledef, package list, Calamares YAML modules, post-install.sh
- bos-settings/: Cargo workspace with GTK4 settings app (8 views: snapshots,
  packages, bread, breadbar, breadbox, breadcrumbs, breadpad, hyprland)

https://claude.ai/code/session_01WszGHvCmxgcyTwNSkfLF9P

src/ui/views/mod.rs

@@ -0,0 +1,8 @@
+pub mod bread;
+pub mod breadbar;
+pub mod breadbox;
+pub mod breadcrumbs;
+pub mod breadpad;
+pub mod hyprland;
+pub mod packages;
+pub mod snapshots;