Docs: groups and roles/permissions architecture, Group moduledoc

- groups-architecture: normal_user and admin can manage groups.
- roles-and-permissions: matrix and MembershipFeeCycle :linked for own_data.
- group_policies_test: update moduledoc.

docs/groups-architecture.md

@@ -420,9 +420,9 @@ lib/
 
 **Actions:**
 - `read` - View groups (all permission sets)
-- `create` - Create groups (admin only)
-- `update` - Edit groups (admin only)
-- `destroy` - Delete groups (admin only)
+- `create` - Create groups (normal_user and admin)
+- `update` - Edit groups (normal_user and admin)
+- `destroy` - Delete groups (normal_user and admin)
 
 **Scopes:**
 - `:all` - All groups (for all permission sets that have read access)
@@ -444,7 +444,7 @@ lib/
 **Own Data Permission Set:**
 - `read` action on `Group` resource with `:all` scope - granted
 
-**Note:** All permission sets use `:all` scope for groups. Groups are considered public information that all users with member read permission can view. Only admins can manage (create/update/destroy) groups.
+**Note:** All permission sets use `:all` scope for groups. Groups are considered public information that all users with member read permission can view. normal_user and admin can manage (create/update/destroy) groups.
 
 ### Member-Group Association Permissions