Reserve a distinct one-shot A01 evaluation label

Why: Reusing an exhausted authorization label would overwrite or misattribute the next controlled quality sample.

Evidence: New label/output and 30000-token guarded-run tests failed before implementation and passed after; full Backend Go suite passed.

Impact: The r0.2 A01 harness can be used only after separate resource approval, with an independent output name and existing two-run guard.

Refs: U3 quality implementation plan r0.2, Task 6 preparation

eval/live/work_checkpoints_test.go

@@ -33,6 +33,9 @@ func checkpointEvalOutputName(filter, authorization string) (string, bool) {
 	if filter == "A01" && authorization == "approved-followup-20261013" {
 		return "candidate-followup-a01", true
 	}
+	if filter == "A01" && authorization == "approved-r02-20261013" {
+		return "candidate-r02-a01", true
+	}
 	if filter == "A02,A04" {
 		return "candidate-remaining", true
 	}
@@ -82,6 +85,7 @@ func TestFollowupA01KeepsItsOwnOneShotResult(t *testing.T) {
 	}{
 		{"A01", "approved-20261013", "candidate-extra-a01", true},
 		{"A01", "approved-followup-20261013", "candidate-followup-a01", true},
+		{"A01", "approved-r02-20261013", "candidate-r02-a01", true},
 		{"A01", "", "", false},
 		{"A01", "unknown", "", false},
 		{"A02,A04", "", "candidate-remaining", true},

internal/server/work_checkpoint_eval_budget_test.go

@@ -102,6 +102,7 @@ func TestFollowupA01UsesNewBoundedAuthorization(t *testing.T) {
 		{"", 20000, false},
 		{"approved-20261013", 20000, true},
 		{"approved-followup-20261013", 30000, true},
+		{"approved-r02-20261013", 30000, true},
 		{"unapproved", 20000, false},
 	} {
 		tokens, guard := evalA01Budget(tc.label)

internal/server/work_checkpoint_eval_test.go

@@ -47,7 +47,7 @@ func evalA01Budget(label string) (int, bool) {
 	switch label {
 	case "approved-20261013":
 		return 20000, true
-	case "approved-followup-20261013":
+	case "approved-followup-20261013", "approved-r02-20261013":
 		return 30000, true
 	default:
 		return 20000, false