Rename vendor action button Fin -> Ship

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

lib/render.php

@@ -146,7 +146,7 @@ function render_actions(array $r, string $audience): string {
             $btns[] = '<button class="btn btn-ack" data-action="acknowledge">Acknowledge</button>';
         }
         if ($r['status'] === '') {
-            $btns[] = '<button class="btn btn-finish" data-action="mark_finished">Fin</button>';
+            $btns[] = '<button class="btn btn-finish" data-action="mark_finished">Ship</button>';
         } elseif ($r['status'] === 'Finished') {
             $btns[] = '<button class="btn btn-ship" data-action="mark_shipped">Shipd</button>';
         }