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>

cmd/setup/03.go

@@ -24,7 +24,7 @@ type FirstInstance struct {
 	Org             command.InstanceOrgSetup
 	MachineKeyPath  string
 	PatPath         string
-	Features        map[domain.Feature]any
+	Features        *command.InstanceFeatures
 
 	instanceSetup     command.InstanceSetup
 	userEncryptionKey *crypto.KeyConfig

cmd/setup/config.go

@@ -19,7 +19,6 @@ import (
 	"github.com/zitadel/zitadel/internal/config/hook"
 	"github.com/zitadel/zitadel/internal/config/systemdefaults"
 	"github.com/zitadel/zitadel/internal/database"
-	"github.com/zitadel/zitadel/internal/domain"
 	"github.com/zitadel/zitadel/internal/eventstore"
 	"github.com/zitadel/zitadel/internal/id"
 	"github.com/zitadel/zitadel/internal/notification/handlers"
@@ -67,7 +66,6 @@ func MustNewConfig(v *viper.Viper) *Config {
 			mapstructure.StringToTimeHookFunc(time.RFC3339),
 			mapstructure.StringToSliceHookFunc(","),
 			database.DecodeHook,
-			hook.EnumHookFunc(domain.FeatureString),
 			hook.EnumHookFunc(authz.MemberTypeString),
 			actions.HTTPConfigDecodeHook,
 			hooks.MapTypeStringDecode[string, *authz.SystemAPIUser],
@@ -127,7 +125,6 @@ func MustNewSteps(v *viper.Viper) *Steps {
 			mapstructure.StringToTimeDurationHookFunc(),
 			mapstructure.StringToTimeHookFunc(time.RFC3339),
 			mapstructure.StringToSliceHookFunc(","),
-			hook.EnumHookFunc(domain.FeatureString),
 		)),
 	)
 	logging.OnError(err).Fatal("unable to read steps")