refactor(pipeline): ввести Runner интерфейс

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

cmd/synapse-backupper/backup.go

@@ -35,17 +35,7 @@ var (
 	outputWriter  io.Writer = os.Stderr
 )
 
-type pipelineRunner interface {
-	Run(
-		ctx context.Context,
-		pgDumpOpts pgdump.Options,
-		recipients []crypto.RecipientPub,
-		sink domain.Sink,
-		rand io.Reader,
-	) error
-}
-
-func defaultNewRunner(options ...pipeline.Option) pipelineRunner {
+func defaultNewRunner(options ...pipeline.Option) pipeline.Runner {
 	return pipeline.NewRunner(options...)
 }
 
@@ -91,7 +81,8 @@ var backupCmd = &cobra.Command{
 			return fmt.Errorf("load classical public key: %w", err)
 		}
 
-		recipients := []crypto.RecipientPub{pqPub, classicalPub}
+		recipients := make([]crypto.RecipientPub, 0, 2)
+		recipients = append(recipients, pqPub, classicalPub)
 
 		pgDumpOpts := pgdump.Options{
 			Host:          cfg.PG.Host,
@@ -110,7 +101,7 @@ var backupCmd = &cobra.Command{
 			slog.String("output_path", finalPath),
 		)
 
-		sink := newLocalSink(cfg.Backup.Dir)
+		var sink domain.Sink = newLocalSink(cfg.Backup.Dir)
 
 		registry := crypto.NewRegistry()
 		_ = registry.Register(0x0006, func() crypto.KEM { return mlkem768.New() })

cmd/synapse-backupper/backup_test.go

@@ -183,7 +183,7 @@ func TestBackupCmd_Success(t *testing.T) {
 
 	testData := []byte("test backup payload")
 	dumper := &successDumper{data: testData}
-	newRunner = func(...pipeline.Option) pipelineRunner {
+	newRunner = func(...pipeline.Option) pipeline.Runner {
 		return pipeline.NewRunner(
 			pipeline.WithDumper(dumper),
 			pipeline.WithEncryptor(&passthroughEncryptor{}),
@@ -320,7 +320,7 @@ func TestBackupCmd_PgDumpFailure(t *testing.T) {
 		return mockKM
 	}
 
-	newRunner = func(...pipeline.Option) pipelineRunner {
+	newRunner = func(...pipeline.Option) pipeline.Runner {
 		return pipeline.NewRunner(
 			pipeline.WithDumper(&failDumper{}),
 			pipeline.WithEncryptor(&passthroughEncryptor{}),

pkg/adapters/pipeline/pipeline.go

@@ -9,6 +9,18 @@ import (
 	"git.tswf.io/infra/go-synapse-backupper/pkg/domain/pgdump"
 )
 
+// Runner orchestrates the dump → encrypt → sink pipeline.
+type Runner interface {
+	// Run executes the full backup pipeline: pg_dump → encrypt → sink.
+	Run(
+		ctx context.Context,
+		pgDumpOpts pgdump.Options,
+		recipients []crypto.RecipientPub,
+		sink domain.Sink,
+		rand io.Reader,
+	) error
+}
+
 // Option configures a Runner.
 type Option func(*runner)
 
@@ -26,14 +38,14 @@ func WithEncryptor(encryptor crypto.Encryptor) Option {
 	}
 }
 
-// Runner orchestrates the dump → encrypt → sink pipeline.
+// runner is the private implementation of Runner.
 type runner struct {
 	dumper    pgdump.Dumper
 	encryptor crypto.Encryptor
 }
 
 // NewRunner creates a pipeline runner with the given functional options.
-func NewRunner(options ...Option) *runner {
+func NewRunner(options ...Option) Runner {
 	r := &runner{}
 	for _, option := range options {
 		option(r)