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/setup.php

@@ -259,7 +259,7 @@ $page_title = $session ? 'Edit Session' : 'New Session';
         </main>
     </div>
 
-    <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/setup.js?v=5"></script>
 </body>
 </html>