Fix ansible-lint violations: FQCN, formatting, bugs, role renames

- Auto-fix FQCN, YAML formatting, jinja spacing, and free-form module
  syntax via ansible-lint --fix
- Fix comments misplaced inside module args by the auto-fixer
  (bluetooth-monitor, pi_standard_setup, pi_musicmouse)
- Fix notify: references left stale (lowercase) after handler names
  were re-cased, which would have silently broken reboot/restart
  handlers (pi_disable_onboard_bluetooth, pi_hifiberry_amp,
  pi_squeezelite, pi_standard_setup)
- Fix a task in pis/debmatic-install.yml missing its module name
  (apt_repository), which caused a real syntax-check failure
- Add missing play names, fix comment spacing, literal-compare idiom,
  and no-changed-when annotations
- Delete unused/broken roles/better-shell-env (unreferenced, invalid YAML)
- Rename all hyphenated role directories to underscore form to satisfy
  ansible-lint's role-name rule, updating every playbook/meta reference

Remaining lint findings (var-naming, package-latest, risky-file-permissions,
no-handler) intentionally left for follow-up per user decision.

working.yml

@@ -1,33 +1,38 @@
 ---
-
-- hosts: server
+- name: Server
+  hosts: server
   roles:
-    - bluetooth-monitor
+    - bluetooth_monitor
 
-- hosts: musikserverwohnzimmeroben
+- name: Musikserver Wohnzimmer oben
+  hosts: musikserverwohnzimmeroben
   roles:
-    - bluetooth-monitor
+    - bluetooth_monitor
 
-- hosts: kitchenpi  
+- name: Kitchen pi
+  hosts: kitchenpi
   roles:
-    - pi-disable-onboard-bluetooth
-    - bluetooth-monitor
+    - pi_disable_onboard_bluetooth
+    - bluetooth_monitor
 
-- hosts: bedroompi
+- name: Bedroom pi
+  hosts: bedroompi
   roles:
-    - pi-disable-onboard-bluetooth
-    - bluetooth-monitor
+    - pi_disable_onboard_bluetooth
+    - bluetooth_monitor
 
-- hosts: musicmouse
+- name: Musicmouse
+  hosts: musicmouse
   roles:
-    - pi-standard-setup
-    - pi-hifiberry-amp
-    - pi-musicmouse
-    - pi-squeezelite-custom
-    - pi-shairport
-    - pi-lirc
-    - bluetooth-monitor
+    - pi_standard_setup
+    - pi_hifiberry_amp
+    - pi_musicmouse
+    - pi_squeezelite_custom
+    - pi_shairport
+    - pi_lirc
+    - bluetooth_monitor
 
-- hosts: homeassistant
+- name: Home Assistant
+  hosts: homeassistant
   roles:
-    - bluetooth-monitor
+    - bluetooth_monitor