Bump photo-crop.js cache-busting version to v=3

Forces a re-fetch of the pan/zoom fix from the previous commit —
learned this lesson the hard way earlier in this same feature.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

admin/builder.php

@@ -308,7 +308,7 @@ var EXISTING_STEPS   = <?= json_encode(array_map(fn($s) => [
     'attribution' => $s['attribution'] ?? 'leader_all',
 ], $edit_steps)) ?>;
 </script>
-<script src="<?= BASE_URL ?>/assets/js/photo-crop.js?v=2"></script>
+<script src="<?= BASE_URL ?>/assets/js/photo-crop.js?v=3"></script>
 <script src="<?= BASE_URL ?>/assets/js/builder.js?v=1"></script>
 </body>
 </html>