feat: register the Users admin screen with the privileged-member guard

- permissions (the four Winter codes and manage_privileged_groups),
  the user navigation item and the embedded admin YAML
- Users controller: list with deactivated users, row states, the
  groups, created date and activated filters, and the form's name,
  surname and email
- a member of a group in golem15.user.privileged_groups (default
  admin) keeps their email, password and row unless the administrator
  holds golem15.users.manage_privileged_groups; the refusal is a 403
  that saves nothing

controllers/users/config_filter.yaml

@@ -0,0 +1,14 @@
+scopes:
+    groups:
+        label: golem15.user::lang.group.label
+        modelClass: Golem15\User\Models\UserGroup
+        nameFrom: name
+        scope: filterByGroup
+    created_date:
+        label: golem15.user::lang.user.created_at
+        type: daterange
+        column: created_at
+    activated:
+        label: golem15.user::lang.user.status_activated
+        type: switch
+        column: is_activated

controllers/users/config_form.yaml

@@ -0,0 +1,14 @@
+name: golem15.user::lang.user.label
+form: ~/plugins/golem15/user/models/user/fields.yaml
+modelClass: Golem15\User\Models\User
+defaultRedirect: golem15/user/users
+
+update:
+    redirect: golem15/user/users/update/:id
+    redirectClose: golem15/user/users
+
+messages:
+    update: backend::lang.messages.form.update
+    saved: backend::lang.messages.form.saved
+    deleteConfirm: golem15.user::lang.users.delete_confirm
+    deleted: backend::lang.messages.form.deleted

controllers/users/config_list.yaml

@@ -0,0 +1,20 @@
+list: ~/plugins/golem15/user/models/user/columns.yaml
+modelClass: Golem15\User\Models\User
+title: golem15.user::lang.users.list_title
+recordUrl: golem15/user/users/update/:id
+noRecordsMessage: backend::lang.list.no_records
+recordsPerPage: 20
+showCheckboxes: true
+showSetup: true
+filter: config_filter.yaml
+
+toolbar:
+    buttons: []
+    search:
+        prompt: backend::lang.list.search_prompt
+
+messages:
+    empty: golem15.user::lang.users.list_empty
+    rowStateDeleted: golem15.user::lang.users.state_deactivated
+    rowStateNegative: golem15.user::lang.users.state_banned
+    rowStateDisabled: golem15.user::lang.users.state_not_activated