feat(bind9): support systemd drop-ins

Keep role configuration namespaced and allow hosts to customize systemd startup.

Co-authored-by: Copilot <copilot@github.com>

tasks/template_zone_files.yaml

@@ -2,9 +2,9 @@
 
 - name: "Create config directory of DNS zones"
   ansible.builtin.file:
-    path: "{{ bind_config_directory }}/{{ zone.file | dirname }}"
-    owner: "{{ bind_unix_user }}"
-    group: "{{ bind_unix_group }}"
+    path: "{{ bind9_config_directory }}/{{ zone.file | dirname }}"
+    owner: "{{ bind9_unix_user }}"
+    group: "{{ bind9_unix_group }}"
     mode: "0755"
     state: directory
   with_items:
@@ -17,9 +17,9 @@
 - name: "Template view {{ view.name }}"
   ansible.builtin.template:
     src: "{{ inventory_hostname }}/etc/named/{{ zone.file }}.j2"
-    dest: "{{ bind_config_directory + '/' + zone.file }}"
-    owner: "{{ bind_unix_user }}"
-    group: "{{ bind_unix_group }}"
+    dest: "{{ bind9_config_directory + '/' + zone.file }}"
+    owner: "{{ bind9_unix_user }}"
+    group: "{{ bind9_unix_group }}"
     mode: "0644"
   with_items:
   - "{{ view.zones }}"