Implemented the initial Go framework

internal/builtin/postprocess.go

@@ -0,0 +1,47 @@
+package builtin
+
+import (
+	"context"
+
+	"gitea.maximumdirect.net/eric/seriatim/internal/config"
+	"gitea.maximumdirect.net/eric/seriatim/internal/model"
+	"gitea.maximumdirect.net/eric/seriatim/internal/report"
+)
+
+type noopPostprocessor struct {
+	name string
+}
+
+func (p noopPostprocessor) Name() string {
+	return p.name
+}
+
+func (p noopPostprocessor) Process(ctx context.Context, in model.MergedTranscript, cfg config.Config) (model.MergedTranscript, []report.Event, error) {
+	if err := ctx.Err(); err != nil {
+		return model.MergedTranscript{}, nil, err
+	}
+
+	return in, []report.Event{
+		report.Info("postprocessing", p.name, "completed no-op postprocessing module"),
+	}, nil
+}
+
+type assignIDs struct{}
+
+func (assignIDs) Name() string {
+	return "assign-ids"
+}
+
+func (assignIDs) Process(ctx context.Context, in model.MergedTranscript, cfg config.Config) (model.MergedTranscript, []report.Event, error) {
+	if err := ctx.Err(); err != nil {
+		return model.MergedTranscript{}, nil, err
+	}
+
+	for index := range in.Segments {
+		in.Segments[index].ID = index + 1
+	}
+
+	return in, []report.Event{
+		report.Info("postprocessing", "assign-ids", "assigned final segment IDs"),
+	}, nil
+}