perf(actionsv2): execution target router (#10564)

# Which Problems Are Solved

The event execution system currently uses a projection handler that
subscribes to and processes all events for all instances. This creates a
high static cost because the system over-fetches event data, handling
many events that are not needed by most instances. This inefficiency is
also reflected in high "rows returned" metrics in the database.

# How the Problems Are Solved

Eliminate the use of a project handler. Instead, events for which
"execution targets" are defined, are directly pushed to the queue by the
eventstore. A Router is populated in the Instance object in the authz
middleware.

- By joining the execution targets to the instance, no additional
queries are needed anymore.
- As part of the instance object, execution targets are now cached as
well.
- Events are queued within the same transaction, giving transactional
guarantees on delivery.
- Uses the "insert many fast` variant of River. Multiple jobs are queued
in a single round-trip to the database.
- Fix compatibility with PostgreSQL 15

# Additional Changes

- The signing key was stored as plain-text in the river job payload in
the DB. This violated our [Secrets
Storage](https://zitadel.com/docs/concepts/architecture/secrets#secrets-storage)
principle. This change removed the field and only uses the encrypted
version of the signing key.
- Fixed the target ordering from descending to ascending.
- Some minor linter warnings on the use of `io.WriteString()`.

# Additional Context

- Introduced in https://github.com/zitadel/zitadel/pull/9249
- Closes https://github.com/zitadel/zitadel/issues/10553
- Closes https://github.com/zitadel/zitadel/issues/9832
- Closes https://github.com/zitadel/zitadel/issues/10372
- Closes https://github.com/zitadel/zitadel/issues/10492

---------

Co-authored-by: Stefan Benz <[email protected]>

internal/api/oidc/op.go

@@ -108,6 +108,7 @@ func NewServer(
 	query *query.Queries,
 	repo repository.Repository,
 	encryptionAlg crypto.EncryptionAlgorithm,
+	targetEncryptionAlgorithm crypto.EncryptionAlgorithm,
 	cryptoKey []byte,
 	es *eventstore.Eventstore,
 	userAgentCookie, instanceHandler func(http.Handler) http.Handler,
@@ -162,6 +163,7 @@ func NewServer(
 		fallbackLogger:             fallbackLogger,
 		hasher:                     hasher,
 		encAlg:                     encryptionAlg,
+		targetEncryptionAlgorithm:  targetEncryptionAlgorithm,
 		opCrypto:                   op.NewAESCrypto(opConfig.CryptoKey),
 		assetAPIPrefix:             assets.AssetAPI(),
 	}

internal/api/oidc/server.go

@@ -36,11 +36,12 @@ type Server struct {
 	defaultIdTokenLifetime     time.Duration
 	jwksCacheControlMaxAge     time.Duration
 
-	fallbackLogger      *slog.Logger
-	hasher              *crypto.Hasher
-	signingKeyAlgorithm string
-	encAlg              crypto.EncryptionAlgorithm
-	opCrypto            op.Crypto
+	fallbackLogger            *slog.Logger
+	hasher                    *crypto.Hasher
+	signingKeyAlgorithm       string
+	encAlg                    crypto.EncryptionAlgorithm
+	targetEncryptionAlgorithm crypto.EncryptionAlgorithm
+	opCrypto                  op.Crypto
 
 	assetAPIPrefix func(ctx context.Context) string
 }

internal/api/oidc/userinfo.go

@@ -429,10 +429,8 @@ func (s *Server) userinfoFlows(ctx context.Context, qu *query.OIDCUserInfo, user
 	if function == "" {
 		return nil
 	}
-	executionTargets, err := execution.QueryExecutionTargetsForFunction(ctx, s.query, function)
-	if err != nil {
-		return err
-	}
+
+	executionTargets := execution.QueryExecutionTargetsForFunction(ctx, function)
 	info := &ContextInfo{
 		Function:     function,
 		UserInfo:     userInfo,
@@ -443,7 +441,7 @@ func (s *Server) userinfoFlows(ctx context.Context, qu *query.OIDCUserInfo, user
 		UserGrants:   qu.UserGrants,
 	}
 
-	resp, err := execution.CallTargets(ctx, executionTargets, info)
+	resp, err := execution.CallTargets(ctx, executionTargets, info, s.targetEncryptionAlgorithm)
 	if err != nil {
 		return err
 	}