Only restart samba when its config changes

state: restarted is unconditional, so every run reported a change and bounced
smbd - which is the share the music is copied over, so a run during a transfer
would interrupt it. Start/enable it as a task, restart it from a handler the
config copy notifies.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

roles/pi_musicmouse/handlers/main.yml

@@ -34,3 +34,9 @@
     state: restarted
     enabled: "yes"
     daemon_reload: "yes"
+
+- name: Restart samba
+  ansible.builtin.systemd:
+    name: smbd
+    state: restarted
+    daemon_reload: true