Add Seriatim input module skeleton

internal/modules/input/seriatim/model.go

@@ -0,0 +1,29 @@
+package seriatim
+
+import (
+	"bytes"
+	"encoding/json"
+)
+
+type transcript struct {
+	Metadata map[string]any `json:"metadata"`
+	Segments []segment      `json:"segments"`
+}
+
+type segment struct {
+	ID      string      `json:"id"`
+	Start   json.Number `json:"start"`
+	End     json.Number `json:"end"`
+	Speaker string      `json:"speaker"`
+	Text    string      `json:"text"`
+}
+
+func decodeTranscript(raw []byte) (transcript, error) {
+	var out transcript
+	decoder := json.NewDecoder(bytes.NewReader(raw))
+	decoder.UseNumber()
+	if err := decoder.Decode(&out); err != nil {
+		return transcript{}, err
+	}
+	return out, nil
+}