ops(ci): automate testing and container image releases

Add PostgreSQL-backed Go validation for application changes and semantic-version release publishing to GHCR.

Default deployments to the public image and prevent host setup from starting the application before deployment.

ansible/roles/app/tasks/main.yml

@@ -61,9 +61,9 @@
     XDG_RUNTIME_DIR: "/run/user/{{ app_user_uid }}"
   changed_when: false
 
-- name: Enable application service
+- name: Enable application service without starting it
   ansible.builtin.command:
-    argv: [systemctl, --user, enable, --now, app-todo.service]
+    argv: [systemctl, --user, enable, app-todo.service]
   become_user: "{{ app_user }}"
   environment:
     XDG_RUNTIME_DIR: "/run/user/{{ app_user_uid }}"