feat: uniform system.content source schema across installers and repositories

roles/global_defaults/tasks/system.yml

@@ -50,23 +50,28 @@
   ansible.builtin.set_fact:
     system_cfg: "{{ system_defaults | combine(system | default({}), recursive=True) | combine(system_cfg, recursive=True) }}"
 
-- name: Apply mirror default for pre-computed system_cfg
+- name: Apply content-source family defaults for pre-computed system_cfg
   when:
     - system_cfg is defined
     - _bootstrap_needs_enrichment | default(false) | bool
-    - system_cfg.mirror | default('') | string | trim | length == 0
   vars:
-    # Same as _normalize_system.yml - kept in sync manually.
+    # Same family resolution as _normalize_system.yml - kept in sync manually.
     _mirror_defaults:
       debian: "https://deb.debian.org/debian/"
       ubuntu: "http://archive.ubuntu.com/ubuntu/"
       ubuntu-lts: "http://archive.ubuntu.com/ubuntu/"
+    _os: "{{ system_cfg.os | default('') | string | lower }}"
   ansible.builtin.set_fact:
     system_cfg: >-
       {{
-        system_cfg | combine({
-          'mirror': _mirror_defaults[system_cfg.os | default('') | string | lower] | default('')
-        }, recursive=True)
+        system_cfg | combine({'content': {
+          'source': system_cfg.content.source
+                    if (system_cfg.content.source | default('') | string | trim | length > 0)
+                    else ('dvd' if _os == 'rhel' else 'mirror'),
+          'url': system_cfg.content.url
+                 if (system_cfg.content.url | default('') | string | trim | length > 0)
+                 else (_mirror_defaults[_os] | default('')),
+        }}, recursive=True)
       }}
 
 - name: Populate primary network fields from first interface (pre-computed)