fix(promo-codes): step-3 review follow-ups

Two findings from Codex audit of 999eec1:

1. BUG — ApplyPromoCodeTask's pointer comment referenced
   tests/Unit/Services/ApplyPromoCodeTaskConcurrencyTest, a file
   deleted in the same commit. Repoint at the new location,
   tests/Unit/Services/PreProcessReservationTaskConcurrencyTest.
   (Patch applied by Codex.)

2. CONCERN — coverage parity lost the "single order qty > limit
   with no prior reservation row" case from the deleted
   ApplyPromoCodeTaskQuantityPerAccountTest::testRejectsWhenOrderExceedsLimit.
   Restore that branch via a new PreProcessReservation test:
   testSingleOrderExceedingLimitRejects (limit=1, prior=null,
   qty=2 → reject; repo `add` must never be called).

Now 7/7 passing in PreProcessReservationTaskConcurrencyTest.

Author: caseylocker

app/Services/Model/Imp/SummitOrderService.php

@@ -820,8 +820,8 @@ public function run(array $formerState): array
                 // PESSIMISTIC_WRITE row lock on the promo code, BEFORE ReserveOrderTask
                 // commits tickets. A post-facto count here (as this task did prior to
                 // the TOCTOU fix) cannot distinguish the current order's freshly-
-                // committed tickets from a concurrent order's — see smarcet's
-                // reproduction in tests/Unit/Services/ApplyPromoCodeTaskConcurrencyTest.
+                // committed tickets from a concurrent order's — see the reproduced
+                // scenario now covered in tests/Unit/Services/PreProcessReservationTaskConcurrencyTest.
 
                 Log::debug(sprintf("adding %s usage to promo code %s", $qty, $promo_code->getId()));
 

tests/Unit/Services/PreProcessReservationTaskConcurrencyTest.php

@@ -131,6 +131,29 @@ public function testSecondReserveRejectsOverLimit(): void
         ]);
     }
 
+    /**
+     * A single first-time request with qty > limit must be rejected
+     * even when there is no prior reservation row. Limit=1, qty=2,
+     * check: 0 + 2 > 1 true → reject. The repo's `add` must NOT be
+     * called since we never reach the persist branch.
+     */
+    public function testSingleOrderExceedingLimitRejects(): void
+    {
+        [$promoCode, $owner, $promoRepo, $reservationRepo, $tx] =
+            $this->buildCollaborators(limit: 1, priorReservation: null);
+
+        $reservationRepo->shouldReceive('add')->never();
+
+        $task = $this->buildTask(owner: $owner, promoRepo: $promoRepo, reservationRepo: $reservationRepo, tx: $tx);
+
+        $this->expectException(ValidationException::class);
+        $this->expectExceptionMessageMatches('/reached the maximum of 1/');
+
+        $this->invokeReserve($task, [
+            'DOMAIN-CODE-1' => ['qty' => 2, 'types' => [42]],
+        ]);
+    }
+
     /**
      * Limit=2, prior qty_used=1 (from a previous Task A), this
      * request qty=1. Check: 1 + 1 > 2 false → pass, increment by 1.