fix(go): batch durable kafka replay

go/vehicle-gateway/internal/eventbus/durable_sink_test.go

@@ -139,6 +139,34 @@ func TestDurableSinkReplayLoopTickRespectsBatchSize(t *testing.T) {
 	}
 }
 
+func TestDurableSinkReplayUsesBatchPublisherWhenAvailable(t *testing.T) {
+	dir := t.TempDir()
+	env := durableTestEnvelope()
+	writeDurableRecord(t, filepath.Join(dir, "0001-raw.json"), durableRecord{Kind: "raw", Envelope: env})
+	writeDurableRecord(t, filepath.Join(dir, "0002-unified.json"), durableRecord{Kind: "unified", Envelope: env})
+	delegate := &batchRecordingSink{}
+	sink := NewDurableSink(delegate, DurableConfig{Directory: dir})
+
+	if err := sink.ReplayOnce(context.Background()); err != nil {
+		t.Fatalf("ReplayOnce() error = %v", err)
+	}
+	if delegate.batchCalls != 1 {
+		t.Fatalf("batch calls = %d, want 1", delegate.batchCalls)
+	}
+	if delegate.rawCalls != 0 || delegate.unifiedCalls != 0 {
+		t.Fatalf("individual publish should not be used, raw=%d unified=%d", delegate.rawCalls, delegate.unifiedCalls)
+	}
+	if got, want := len(delegate.records), 2; got != want {
+		t.Fatalf("batch record count = %d, want %d", got, want)
+	}
+	if delegate.records[0].Kind != "raw" || delegate.records[1].Kind != "unified" {
+		t.Fatalf("batch order = %#v", delegate.records)
+	}
+	if files := spoolFiles(t, dir); len(files) != 0 {
+		t.Fatalf("spool files after replay = %#v, want none", files)
+	}
+}
+
 func TestDurableFilesFromReaderStopsAfterLimitedJSONBatch(t *testing.T) {
 	reader := &fakeNameReader{
 		batches: [][]string{
@@ -298,3 +326,30 @@ func (s *contextCheckingReplaySink) PublishUnified(ctx context.Context, _ envelo
 func (s *contextCheckingReplaySink) Close() error {
 	return nil
 }
+
+type batchRecordingSink struct {
+	batchCalls   int
+	records      []durableRecord
+	rawCalls     int
+	unifiedCalls int
+}
+
+func (s *batchRecordingSink) PublishRecords(_ context.Context, records []durableRecord) error {
+	s.batchCalls++
+	s.records = append(s.records, records...)
+	return nil
+}
+
+func (s *batchRecordingSink) PublishRaw(context.Context, envelope.FrameEnvelope) error {
+	s.rawCalls++
+	return nil
+}
+
+func (s *batchRecordingSink) PublishUnified(context.Context, envelope.FrameEnvelope) error {
+	s.unifiedCalls++
+	return nil
+}
+
+func (s *batchRecordingSink) Close() error {
+	return nil
+}