mavend: centralize action validation boundary (slice 4)

cmd/mavend/actionresolve.go

@@ -52,3 +52,40 @@ func noteActionResolution(ctx context.Context, source, fn string, resolved bool)
 		Reason:   reason,
 	})
 }
+
+// noteActionValidation records the structural validation outcome in the
+// decision trace. Three outcomes: unresolved (matcher miss), valid
+// (structurally admissible), or invalid (structurally malformed).
+func noteActionValidation(ctx context.Context, v router.ActionValidationResult) {
+	rec := decision.From(ctx)
+	if rec == nil {
+		return
+	}
+	switch {
+	case v.Unresolved:
+		rec.Note(decision.Claim{
+			Stage:    decision.StageAction,
+			Claimant: "action-validation",
+			Outcome:  decision.Declined,
+			Reason:   "unresolved",
+		})
+	case v.Valid:
+		rec.Note(decision.Claim{
+			Stage:    decision.StageAction,
+			Claimant: "action-validation",
+			Outcome:  decision.Won,
+			Reason:   "valid",
+		})
+	default:
+		reason := "invalid"
+		if len(v.Issues) > 0 {
+			reason = "invalid:" + v.Issues[0].Reason
+		}
+		rec.Note(decision.Claim{
+			Stage:    decision.StageAction,
+			Claimant: "action-validation",
+			Outcome:  decision.Declined,
+			Reason:   reason,
+		})
+	}
+}