Initialize narratio Go module and CLI scaffold

internal/contracts/transcript.go

@@ -0,0 +1,19 @@
+package contracts
+
+// SpeakerTranscript is a placeholder transcription artifact contract.
+type SpeakerTranscript struct {
+	Schema    string `json:"schema"`
+	SessionID string `json:"session_id"`
+}
+
+// CanonicalTranscript is a placeholder merged transcript contract.
+type CanonicalTranscript struct {
+	Schema    string `json:"schema"`
+	SessionID string `json:"session_id"`
+}
+
+// ProcessedTranscript is a placeholder polished transcript contract.
+type ProcessedTranscript struct {
+	Schema    string `json:"schema"`
+	SessionID string `json:"session_id"`
+}