feat(login): use default org for login without provided org context (#6625)

* start feature flags

* base feature events on domain const

* setup default features

* allow setting feature in system api

* allow setting feature in admin api

* set settings in login based on feature

* fix rebasing

* unit tests

* i18n

* update policy after domain discovery

* some changes from review

* check feature and value type

* check feature and value type

feature/check.go

@@ -0,0 +1,45 @@
+package feature
+
+import (
+	"context"
+
+	"github.com/zitadel/zitadel/internal/api/authz"
+	"github.com/zitadel/zitadel/internal/command"
+	"github.com/zitadel/zitadel/internal/command/preparation"
+	"github.com/zitadel/zitadel/internal/domain"
+	"github.com/zitadel/zitadel/internal/eventstore"
+	"github.com/zitadel/zitadel/internal/repository/feature"
+)
+
+type Checker interface {
+	CheckInstanceBooleanFeature(ctx context.Context, f domain.Feature) (feature.Boolean, error)
+}
+
+func NewCheck(eventstore *eventstore.Eventstore) *Check {
+	return &Check{eventstore: eventstore}
+}
+
+type Check struct {
+	eventstore *eventstore.Eventstore
+}
+
+func (c *Check) CheckInstanceBooleanFeature(ctx context.Context, f domain.Feature) (feature.Boolean, error) {
+	return getInstanceFeature[feature.Boolean](ctx, f, c.eventstore.Filter)
+}
+
+func getInstanceFeature[T feature.SetEventType](ctx context.Context, f domain.Feature, filter preparation.FilterToQueryReducer) (T, error) {
+	instanceID := authz.GetInstance(ctx).InstanceID()
+	writeModel, err := command.NewInstanceFeatureWriteModel[T](instanceID, f)
+	if err != nil {
+		return writeModel.Value, err
+	}
+	events, err := filter(ctx, writeModel.Query())
+	if err != nil {
+		return writeModel.Value, err
+	}
+	writeModel.AppendEvents(events...)
+	if err = writeModel.Reduce(); err != nil {
+		return writeModel.Value, err
+	}
+	return writeModel.Value, nil
+}