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

dotfiles/hyprland/keybinds.conf

@@ -0,0 +1,58 @@
+$mod = SUPER
+
+# App launchers
+bind = $mod, Space, exec, breadbox
+bind = $mod, N, exec, breadpad
+bind = $mod, M, exec, breadman
+bind = $mod, S, exec, bos-settings
+
+# Core
+bind = $mod, Return, exec, foot
+bind = $mod, Q, killactive
+bind = $mod SHIFT, E, exit
+bind = $mod, F, fullscreen
+
+# Focus
+bind = $mod, H, movefocus, l
+bind = $mod, L, movefocus, r
+bind = $mod, K, movefocus, u
+bind = $mod, J, movefocus, d
+
+# Move windows
+bind = $mod SHIFT, H, movewindow, l
+bind = $mod SHIFT, L, movewindow, r
+bind = $mod SHIFT, K, movewindow, u
+bind = $mod SHIFT, J, movewindow, d
+
+# Workspaces
+bind = $mod, 1, workspace, 1
+bind = $mod, 2, workspace, 2
+bind = $mod, 3, workspace, 3
+bind = $mod, 4, workspace, 4
+bind = $mod, 5, workspace, 5
+
+bind = $mod SHIFT, 1, movetoworkspace, 1
+bind = $mod SHIFT, 2, movetoworkspace, 2
+bind = $mod SHIFT, 3, movetoworkspace, 3
+bind = $mod SHIFT, 4, movetoworkspace, 4
+bind = $mod SHIFT, 5, movetoworkspace, 5
+
+# Scroll through workspaces
+bind = $mod, mouse_down, workspace, e+1
+bind = $mod, mouse_up, workspace, e-1
+
+# Mouse binds
+bindm = $mod, mouse:272, movewindow
+bindm = $mod, mouse:273, resizewindow
+
+# Volume
+bind = , XF86AudioRaiseVolume, exec, wpctl set-volume @DEFAULT_AUDIO_SINK@ 5%+
+bind = , XF86AudioLowerVolume, exec, wpctl set-volume @DEFAULT_AUDIO_SINK@ 5%-
+bind = , XF86AudioMute, exec, wpctl set-mute @DEFAULT_AUDIO_SINK@ toggle
+
+# Brightness
+bind = , XF86MonBrightnessUp, exec, brightnessctl set 5%+
+bind = , XF86MonBrightnessDown, exec, brightnessctl set 5%-
+
+# Screenshot
+bind = , Print, exec, grimblast copy area