Add render artifact model, config, and Seriatim adapter contracts

internal/config/defaults.go

@@ -40,6 +40,12 @@ const (
 
 	DefaultTrimBoundsTimeout  = "10m"
 	DefaultTrimSeriatimReport = false
+	DefaultRenderEnabled      = true
+	DefaultRenderFormat       = "markdown"
+	DefaultRenderTitle        = ""
+	DefaultRenderTimestamps   = true
+	DefaultRenderSegmentIDs   = false
+	DefaultRenderMetadata     = false
 
 	DefaultNormalizeOutputPath   = artifactmodel.TranscriptPathFinal
 	DefaultNormalizeOutputSchema = "seriatim-intermediate"