Reorganize desktop roles: extract common bootstrap and host-specific layers

- Add profile_desktop_common with shared desktop bootstrap (emptty, PAM,
  dotfiles, templates, GPG, Maildir, Flatpak, st, external tools)
- Add profile_desktop_host with host-specific tasks (NVIDIA/PRIME on nymph)
- Reduce profile_desktop_i3 to i3/X11-only tasks
- Create profile_desktop_hyprland for Hyprland Wayland session
- Add dual-session support (i3 + Hyprland) on nymph with session choice
- Create shared Hyprland/Waybar dotfiles under dotfiles/desktop/
- Fix Waybar: bottom position, no persistent workspaces, sort by number
- Rename host_dotfiles to host_i3_dotfiles for clarity
- Make emptty restart manual by default to avoid session drops

ansible/roles/packages_void/tasks/main.yml

@@ -51,11 +51,23 @@
   community.general.xbps:
     name: >-
       {{
-        (common_packages | default([]))
+        (
+          (common_packages | default([]))
         + (void_packages_base | default([]))
         + (profile_packages | default([]))
-        + (desktop_x11_packages | default([]))
+        + (desktop_common_packages | default([]))
+        + (
+            (desktop_i3_packages | default([]))
+            if 'i3' in (desktop_sessions_enabled | default([]))
+            else []
+          )
+        + (
+            (desktop_hyprland_packages | default([]))
+            if 'hyprland' in (desktop_sessions_enabled | default([]))
+            else []
+          )
         + (host_packages | default([]))
+        ) | unique
       }}
     state: present
     update_cache: false