Carry optional prompt labels through results

requirements.go

@@ -116,7 +116,8 @@ type RequirementIssue struct {
 // prompt context. Input and variable entries are sorted by exact name. Issues
 // are deduplicated by code and associated names, then sorted by that tuple.
 // Their descriptions and entry explanations are safe summaries, not
-// machine-readable details.
+// machine-readable details. PromptVersion is caller-owned: nil means no label
+// was declared; a non-nil empty string is explicit.
 //
 // Complete describes the supported analysis's discovery coverage, not whether
 // requirements are supplied, templates will render, artifacts or schemas are
@@ -128,8 +129,9 @@ type RequirementIssue struct {
 type RequirementInspection struct {
 	// PromptID is the selected exact prompt ID.
 	PromptID string
-	// PromptVersion is the selected definition's descriptive version label.
-	PromptVersion string
+	// PromptVersion is the selected definition's descriptive version label. Nil
+	// means no label was declared; a non-nil empty string is an explicit label.
+	PromptVersion *string
 	// ProfileID is the selected profile identity; it does not indicate
 	// execution readiness.
 	ProfileID string
@@ -200,7 +202,7 @@ func fromDomainRequirementInspection(inspection *domain.RequirementInspection) *
 		return nil
 	}
 	result := &RequirementInspection{
-		PromptID: inspection.PromptID, PromptVersion: inspection.PromptVersion,
+		PromptID: inspection.PromptID, PromptVersion: copyRequirementString(inspection.PromptVersion),
 		ProfileID: inspection.ProfileID, Complete: inspection.Complete,
 		Inputs:    make([]InputRequirement, len(inspection.Inputs)),
 		Variables: make([]VariableRequirement, len(inspection.Variables)),