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/profile_desktop_host/tasks/main.yml

@@ -0,0 +1,35 @@
+---
+- name: Include nymph desktop host tasks
+  tags: [packages, nvidia, dotfiles, dotfiles:host]
+  ansible.builtin.include_tasks: nymph.yml
+  when: hostname == 'nymph'
+
+- name: Copy host-specific i3 dotfiles
+  tags: [dotfiles, dotfiles:desktop, dotfiles:host, i3]
+  ansible.builtin.copy:
+    src: "{{ playbook_dir }}/../dotfiles/{{ hostname }}/{{ item.src }}"
+    dest: "{{ user_home }}/{{ item.dest }}"
+    owner: "{{ username }}"
+    group: "{{ user_group }}"
+    mode: "{{ item.mode }}"
+  loop: "{{ host_i3_dotfiles | default([]) }}"
+  loop_control:
+    label: "{{ item.dest }}"
+  when:
+    - "'i3' in (desktop_sessions_enabled | default([]))"
+    - (host_i3_dotfiles | default([])) | length > 0
+
+- name: Copy host-specific Hyprland dotfiles
+  tags: [dotfiles, dotfiles:desktop, dotfiles:host, hyprland]
+  ansible.builtin.copy:
+    src: "{{ playbook_dir }}/../dotfiles/{{ hostname }}/{{ item.src }}"
+    dest: "{{ user_home }}/{{ item.dest }}"
+    owner: "{{ username }}"
+    group: "{{ user_group }}"
+    mode: "{{ item.mode }}"
+  loop: "{{ host_hyprland_dotfiles | default([]) }}"
+  loop_control:
+    label: "{{ item.dest }}"
+  when:
+    - "'hyprland' in (desktop_sessions_enabled | default([]))"
+    - (host_hyprland_dotfiles | default([])) | length > 0