Permissions: a certificates role

A template for tokens and users that get certificates for other hosts
(jarl cert get): certificates:write, to narrow with names= in the web
UI's "Insert a template…", or --role certificates in the CLI. The token
form's template filter no longer counts "*" as covering certificates,
as the server doesn't.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/auth/auth_test.go

@@ -135,6 +135,16 @@ func TestRoleTemplatesValid(t *testing.T) {
 	}
 }
 
+func TestCertificatesRole(t *testing.T) {
+	p := &Principal{User: &model.User{Grants: RoleTemplates["certificates"]}}
+	if !p.Can(Action{Resource: ResCerts, Write: true, Name: "web01.adbraun.lol"}) {
+		t.Error("the certificates role can't get a certificate")
+	}
+	if p.Can(Action{Resource: ResRecords, Write: true, Zone: "adbraun.lol."}) || p.Can(Action{Resource: ResZones, Zone: "adbraun.lol."}) {
+		t.Error("the certificates role reaches beyond certificates")
+	}
+}
+
 func TestCertificateGrants(t *testing.T) {
 	g, err := ParseGrant("certificates:write names=*.adbraun.lol")
 	if err != nil {