feat(api): feature flags (#7356)

* feat(api): feature API proto definitions

* update proto based on discussion with @livio-a

* cleanup old feature flag stuff

* authz instance queries

* align defaults

* projection definitions

* define commands and event reducers

* implement system and instance setter APIs

* api getter implementation

* unit test repository package

* command unit tests

* unit test Get queries

* grpc converter unit tests

* migrate the V1 features

* migrate oidc to dynamic features

* projection unit test

* fix instance by host

* fix instance by id data type in sql

* fix linting errors

* add system projection test

* fix behavior inversion

* resolve proto file comments

* rename SystemDefaultLoginInstanceEventType to SystemLoginDefaultOrgEventType so it's consistent with the instance level event

* use write models and conditional set events

* system features integration tests

* instance features integration tests

* error on empty request

* documentation entry

* typo in feature.proto

* fix start unit tests

* solve linting error on key case switch

* remove system defaults after discussion with @eliobischof

* fix system feature projection

* resolve comments in defaults.yaml

---------

Co-authored-by: Livio Spring <livio.a@gmail.com>

internal/command/instance_features.go

@@ -0,0 +1,69 @@
+package command
+
+import (
+	"context"
+
+	"github.com/zitadel/zitadel/internal/api/authz"
+	"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/feature_v2"
+	"github.com/zitadel/zitadel/internal/zerrors"
+)
+
+type InstanceFeatures struct {
+	LoginDefaultOrg                 *bool
+	TriggerIntrospectionProjections *bool
+	LegacyIntrospection             *bool
+}
+
+func (m *InstanceFeatures) isEmpty() bool {
+	return m.LoginDefaultOrg == nil &&
+		m.TriggerIntrospectionProjections == nil &&
+		m.LegacyIntrospection == nil
+}
+
+func (c *Commands) SetInstanceFeatures(ctx context.Context, f *InstanceFeatures) (*domain.ObjectDetails, error) {
+	if f.isEmpty() {
+		return nil, zerrors.ThrowInvalidArgument(nil, "COMMAND-Vigh1", "Errors.NoChangesFound")
+	}
+	wm := NewInstanceFeaturesWriteModel(authz.GetInstance(ctx).InstanceID())
+	if err := c.eventstore.FilterToQueryReducer(ctx, wm); err != nil {
+		return nil, err
+	}
+	cmds := wm.setCommands(ctx, f)
+	if len(cmds) == 0 {
+		return writeModelToObjectDetails(wm.WriteModel), nil
+	}
+	events, err := c.eventstore.Push(ctx, cmds...)
+	if err != nil {
+		return nil, err
+	}
+	return pushedEventsToObjectDetails(events), nil
+}
+
+func prepareSetFeatures(instanceID string, f *InstanceFeatures) preparation.Validation {
+	return func() (preparation.CreateCommands, error) {
+		return func(ctx context.Context, _ preparation.FilterToQueryReducer) ([]eventstore.Command, error) {
+			wm := NewInstanceFeaturesWriteModel(instanceID)
+			return wm.setCommands(ctx, f), nil
+		}, nil
+	}
+}
+
+func (c *Commands) ResetInstanceFeatures(ctx context.Context) (*domain.ObjectDetails, error) {
+	instanceID := authz.GetInstance(ctx).InstanceID()
+	wm := NewInstanceFeaturesWriteModel(instanceID)
+	if err := c.eventstore.FilterToQueryReducer(ctx, wm); err != nil {
+		return nil, err
+	}
+	if wm.isEmpty() {
+		return writeModelToObjectDetails(wm.WriteModel), nil
+	}
+	aggregate := feature_v2.NewAggregate(instanceID, instanceID)
+	events, err := c.eventstore.Push(ctx, feature_v2.NewResetEvent(ctx, aggregate, feature_v2.InstanceResetEventType))
+	if err != nil {
+		return nil, err
+	}
+	return pushedEventsToObjectDetails(events), nil
+}