Remove legacy reconciliation path

internal/framework/semanticreconcile/proposal.go

@@ -1,6 +1,9 @@
 package semanticreconcile
 
-import "sort"
+import (
+	"fmt"
+	"sort"
+)
 
 // ProposalResponse is the complete private structured response contract.
 type ProposalResponse struct {
@@ -35,6 +38,16 @@ type Issue struct {
 	Category   IssueCategory
 }
 
+// IssueDetails renders stable, domain-neutral proposal diagnostics for an
+// adapter's retry message.
+func IssueDetails(issues []Issue) []string {
+	details := make([]string, len(issues))
+	for index, issue := range issues {
+		details[index] = fmt.Sprintf("group %d: %s", issue.GroupIndex, issue.Category)
+	}
+	return details
+}
+
 // PlanGroup identifies one validated group using original candidate positions.
 type PlanGroup struct {
 	memberPositions   []int