Stop legacy dta_service systemd units before Docker deploy (#52).

ai-server-4080 runs dta_service active/active with adama and roslin.
Disable beta_dta_wsgi/prod_dta_wsgi so port 8001/8011 are free for compose.

Co-authored-by: Cursor <cursoragent@cursor.com>

roles/app-deploy/tasks/django.yml

@@ -76,6 +76,30 @@
   become_user: "{{ admin_user }}"
   changed_when: true
 
+- name: "django[{{ _project }}] legacy systemd unit"
+  ansible.builtin.set_fact:
+    _legacy_systemd: "{{ _spec.legacy_systemd_units[app_item.env] | default('') }}"
+  when: _spec.legacy_systemd_units is defined
+
+- name: "django[{{ _project }}] probe legacy systemd unit"
+  ansible.builtin.command:
+    cmd: systemctl list-unit-files {{ _legacy_systemd }}.service --no-legend
+  register: _legacy_systemd_probe
+  changed_when: false
+  failed_when: false
+  become: true
+  when: _legacy_systemd | default('') | length > 0
+
+- name: "django[{{ _project }}] stop legacy systemd unit"
+  ansible.builtin.systemd:
+    name: "{{ _legacy_systemd }}"
+    state: stopped
+    enabled: false
+  become: true
+  when:
+    - _legacy_systemd | default('') | length > 0
+    - _legacy_systemd_probe.stdout | default('') | length > 0
+
 - name: "django[{{ _project }}] start containers"
   ansible.builtin.command:
     cmd: "docker compose -f {{ _spec.compose_file }} --env-file .env up -d --remove-orphans"