Enhance Sway/Noctalia integration and align desktop docs

- Add canonical usb-drive-manager plugin to Noctalia (symlink from official)
- Remove nm-applet and blueman packages from nymph Sway session
- Run udiskie without tray (backend for automount/LUKS, UI via usb-drive-manager)
- Add screenOverrides support to Noctalia bar via inventory variables
- Add host_packages_absent task to packages_void role
- Update desktop docs with full plugin list and config layering
- Add focused validation check for Sway/Noctalia bootstrap

ansible/roles/profile_desktop_sway/templates/noctalia-settings.json.j2

@@ -70,7 +70,14 @@
         "rightClickAction": "controlCenter",
         "rightClickCommand": "",
         "rightClickFollowMouse": true,
-        "screenOverrides": [],
+        "screenOverrides": [
+{% for override in noctalia_screen_overrides | default([]) %}
+            {
+                "enabled": {{ override.enabled | lower }},
+                "name": "{{ override.name }}"
+            }{% if not loop.last %},{% endif %}
+{% endfor %}
+        ],
         "showCapsule": true,
         "showOnWorkspaceSwitch": true,
         "showOutline": false,