Add Promptkit execution adapter

internal/promptexec/promptexec.go

@@ -148,6 +148,16 @@ type Validation struct {
 	Diagnostics []string
 }
 
+// NewValidation returns a completed validation value with bounded diagnostics.
+func NewValidation(status ValidationStatus, mode string, schemaPath string, diagnostics []string) Validation {
+	return Validation{
+		Status:      status,
+		Mode:        mode,
+		SchemaPath:  schemaPath,
+		Diagnostics: boundDiagnostics(diagnostics),
+	}
+}
+
 // ValidationStatus identifies the completed validation state.
 type ValidationStatus string