Remove i3 desktop profile and st terminal

Elimina completamente la sessione desktop i3 (X11), ormai non più usata
(gli host espongono solo sway e Hyprland su Wayland):
- ruolo profile_desktop_i3 e voce emptty i3.desktop
- desktop_i3_packages e i guard 'i3' in desktop_sessions_enabled
- desktop_i3_dotfiles e host_i3_dotfiles (autorandr X11)
- dotfiles i3/X11: .xinitrc, i3, i3blocks, picom, polybar, autorandr
- task host-specifici i3 (copy dotfiles, wrap prime-run su nymph)
- rimuove st (terminale X11 da sorgente) da desktop_void_source_tools
- consolida lo script live in scripts/remove_i3.sh, elimina cleanup-i3.sh
- aggiorna la documentazione (README/AGENTS/CLAUDE/knowledge)

Config Emacs lasciata invariata di proposito.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

ansible/roles/packages_void/tasks/main.yml

@@ -56,11 +56,6 @@
         + (void_packages_base | default([]))
         + (profile_packages | default([]))
         + (desktop_common_packages | default([]))
-        + (
-            (desktop_i3_packages | default([]))
-            if 'i3' in (desktop_sessions_enabled | default([]))
-            else []
-          )
         + (
             (desktop_sway_packages | default([]))
             if 'sway' in (desktop_sessions_enabled | default([]))
@@ -83,4 +78,4 @@
   community.general.xbps:
     name: "{{ host_packages_absent | default([]) }}"
     state: absent
-  when: (host_packages_absent | default([])) | length > 0
+  when: (host_packages_absent | default([])) | length > 0