refactor: spell the five permission codes out in the catalog

The catalog reads like the Winter registerPermissions() list, and a
test pins the codes and their default roles.

admin_users_test.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 	"testing"
 
+	"git.golem15.com/golem15/sm-user-plugin/classes"
 	"git.golem15.com/golem15/sm-user-plugin/models"
 	"git.golem15.com/golem15/summercms/modules/compass"
 )
@@ -20,6 +21,27 @@ const (
 // permission gating, the list schema, row states, search, the three filters
 // and an update.
 func TestAdminUsersTracer(t *testing.T) {
+	// The permission catalog: the four Winter codes default to the developer
+	// role, the privileged-groups code to no role at all.
+	var codes []string
+	for _, permission := range (&Plugin{}).Permissions() {
+		role := "-"
+		if len(permission.Roles) == 1 {
+			role = permission.Roles[0]
+		}
+		codes = append(codes, permission.Code+"@"+role)
+		if permission.Tab != "golem15.user::lang.plugin.tab" || !strings.HasPrefix(permission.Label, "golem15.user::lang.plugin.") {
+			t.Fatalf("permission %+v", permission)
+		}
+	}
+	if want := []string{
+		"golem15.users.access_users@developer", "golem15.users.access_groups@developer",
+		"golem15.users.access_settings@developer", "golem15.users.impersonate_user@developer",
+		classes.PermissionManagePrivilegedGroups + "@-",
+	}; !reflect.DeepEqual(codes, want) || classes.PermissionManagePrivilegedGroups != permManagePrivileged {
+		t.Fatalf("permissions = %v", codes)
+	}
+
 	env := newAdminEnv(t)
 	token := env.admin(t, permAccessUsers)
 	stranger := env.admin(t)