Fix primary screen for class room PCs with projector

Fixed EDID modes are set on the HDMI switch (ACER 120Hz problem).
This means that the affected PCs always see a second screen, even if beamer is off.

To avoid confusion, it must be ensured that no information is displayed on invisible devices:
- set primary screen for login dialog
- set primary screen after login
- clone screen
If the primary screen deviates from the standard, this information is maintained via inventory.

In addition, some PCs have different audio autputs than HDMI (or they have multiple HDMI outputs).
It is therefore possible to specify the audio device in the inventory.

roles/lmn_fvs/tasks/main.yml

@@ -229,10 +229,12 @@
 
 - name: Fix primary screen for class room PCs with projector
   block:
-    - name: Switch projector off for login
-      lineinfile:
-        dest: /usr/share/sddm/scripts/Xsetup
-        line: 'xrandr --output {{ dual_screen[0] }} --off'
+    - name: Set primary screen for login
+      blockinfile:
+        path: /usr/share/sddm/scripts/Xsetup
+        block: |
+          xrandr --output {{ dual_screen[0] }} --primary
+      when: dual_screen is defined
     - name: Deploy fix-screen script
       ansible.builtin.template:
         src: lmn-fix-screen.j2
@@ -247,7 +249,7 @@
           Exec=lmn-fix-screen
           Type=Application
           NoDisplay=true
-  when: dual_screen is defined
+  when: groups.CloneScreen is defined and inventory_hostname in groups.CloneScreen
 
 #- name: Avoid starting kscreen (confusing autodetection)
 #  ansible.builtin.copy: