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.

roles/pi_musicmouse/files/config.yml

@@ -0,0 +1,40 @@
+---
+general:
+  alsa_device: softvol_effects
+  mqtt:
+    user: musicmouse
+    password: KNLEFLZF94yA6Zhj141
+    server: homeassistant
+  hass_url: https://ha.bauer.tech
+  hass_token: "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiI4N2ExMzM2ZmQ4ZWQ0ZDgzOWZhMjU3NmZjYTg1NWQ1ZiIsImlhdCI6MTcwNDAyOTUyOSwiZXhwIjoyMDE5Mzg5NTI5fQ.vx9L5bTSey98uc8TwodShaEXSMr-hjXugPsNviR_fEw" # noqa: yaml[line-length]
+  button_leds_brightness: 0.5
+  volume_increment: 5
+  min_volume: 23
+  max_volume: 70
+  serial_port: "/dev/ttyUSB0"
+
+figures:
+  elefant:
+    id: "88041174e9"
+    colors: ["#ffff00", "#00c8ff", "#094b46", "#c20099"]
+  fuchs:
+    id: "8804ce7230"
+    colors: ["#F4D35E", "#F95738", "#F95738", "#083d77"]
+  eule:
+    id: "88040d71f0"
+    colors: ["#e5a200", "#f8e300", "w33", "w99"]
+  omnom:
+    id: "88043c6ede"
+    colors: ["#005102", "#fec800", "#005102", "#3bc405"]
+  eichhoernchen:
+    id: "88040b78ff"
+    colors: ["#ff0ada", "#4BC6B9", "#69045a", "#4BC6B9"]
+  hund:
+    id: "8804bc7444"
+    colors: ["#ffff00", "#00c8ff", "#094b46", "#c20099"]
+  hase:
+    id: "88044670ba"
+    colors: ["#ffff00", "#00c8ff", "#094b46", "#c20099"]
+  schneemann:
+    id: "88043f71c2"
+    colors: ["#ff0ada", "#4BC6B9", "#69045a", "#4BC6B9"]