Finalize conversation and execution group documentation

types.go

@@ -85,9 +85,12 @@ const (
 // own private execution snapshot for RunPrepared. Excessively deep or large
 // JSON-shaped values are rejected for safety.
 type RunRequest struct {
-	// CaptureExchange requests an immutable snapshot of a completed run.
+	// CaptureExchange requests an immutable snapshot of a completed run, even
+	// when its structural validation fails. Operational errors return no result.
 	CaptureExchange bool
 	// ContinueFrom supplies captured history and implies capture of the new run.
+	// A non-nil zero-value exchange is invalid. Follow-up settings are selected
+	// normally and are not inherited from the exchange.
 	ContinueFrom *Exchange `json:"-" yaml:"-"`
 	// PromptID is the required prompt identifier. A namespace-scoped engine view
 	// qualifies a slashless caller value; otherwise it selects the exact