feat: add transactional approval workflow

app/Domain/Reservations/Services/AvailabilityService.php

@@ -25,14 +25,19 @@ class AvailabilityService
                 ->where('ends_at', '>', $startsAt));
     }
 
-    public function isAvailable(SnipeAsset $asset, DateTimeInterface $startsAt, DateTimeInterface $endsAt): bool
-    {
+    public function isAvailable(
+        SnipeAsset $asset,
+        DateTimeInterface $startsAt,
+        DateTimeInterface $endsAt,
+        ?int $exceptReservationId = null,
+    ): bool {
         if (! $asset->active || ! $asset->requestable || $asset->assigned_id !== null) {
             return false;
         }
 
         $hasReservationConflict = $asset->reservationItems()
             ->whereIn('status', ReservationItemStatus::blockingValues())
+            ->when($exceptReservationId, fn (Builder $query): Builder => $query->where('reservation_id', '!=', $exceptReservationId))
             ->where('starts_at', '<', $endsAt)
             ->where('ends_at', '>', $startsAt)
             ->exists();