Add render artifact model, config, and Seriatim adapter contracts

internal/artifacts/transcripts_test.go

@@ -31,6 +31,18 @@ func TestRuntimeTranscriptArtifacts(t *testing.T) {
 			ProducerStage:    "trim",
 			OutputKind:       TranscriptOutputKindFinalTrimmed,
 		},
+		{
+			SourceID:         ArtifactTranscriptFinalMarkdown,
+			CanonicalRelPath: TranscriptPathFinalMarkdown,
+			ProducerStage:    "render",
+			OutputKind:       TranscriptOutputKindFinalMarkdown,
+		},
+		{
+			SourceID:         ArtifactTranscriptFinalTrimmedMarkdown,
+			CanonicalRelPath: TranscriptPathFinalTrimmedMarkdown,
+			ProducerStage:    "render",
+			OutputKind:       TranscriptOutputKindFinalTrimmedMarkdown,
+		},
 	}
 
 	got := RuntimeTranscriptArtifacts()
@@ -75,6 +87,18 @@ func TestPlannedTranscriptArtifacts(t *testing.T) {
 			ProducerStage:    "trim",
 			OutputKind:       TranscriptOutputKindFinalTrimmed,
 		},
+		{
+			SourceID:         ArtifactTranscriptFinalMarkdown,
+			CanonicalRelPath: TranscriptPathFinalMarkdown,
+			ProducerStage:    "render",
+			OutputKind:       TranscriptOutputKindFinalMarkdown,
+		},
+		{
+			SourceID:         ArtifactTranscriptFinalTrimmedMarkdown,
+			CanonicalRelPath: TranscriptPathFinalTrimmedMarkdown,
+			ProducerStage:    "render",
+			OutputKind:       TranscriptOutputKindFinalTrimmedMarkdown,
+		},
 	}
 
 	got := PlannedTranscriptArtifacts()
@@ -113,10 +137,14 @@ func TestRuntimeArtifactRegistryUsesTranscriptSpecs(t *testing.T) {
 		if !ok {
 			t.Fatalf("artifactRegistry missing %q", transcript.SourceID)
 		}
+		wantContentKind := contentTranscriptJSON
+		if transcript.SourceID == ArtifactTranscriptFinalMarkdown || transcript.SourceID == ArtifactTranscriptFinalTrimmedMarkdown {
+			wantContentKind = contentText
+		}
 		if spec.CanonicalRelPath != transcript.CanonicalRelPath ||
 			spec.ProducerStage != transcript.ProducerStage ||
 			spec.OutputKind != transcript.OutputKind ||
-			spec.ContentKind != contentTranscriptJSON {
+			spec.ContentKind != wantContentKind {
 			t.Fatalf("artifactRegistry[%q] = %#v, want transcript spec %#v", transcript.SourceID, spec, transcript)
 		}
 	}