Define _dur on the arrs page — it was calling a function that does not exist

The media jobs row I just added formats durations with _dur(), which the rsync
page defines locally and js/varaverk.js does not export at all. The reference
threw inside _render(), the fetch's catch reported it as "Error loading arrs
status", and the whole page went blank — nothing to do with the API, which was
returning valid JSON throughout.

Plugin/unraid/pages/arrs.php

@@ -374,6 +374,18 @@ function _syncSection(sync, recovery, settings) {
   </div>`;
 }
 
+// Local, because there is no global one. js/varaverk.js provides _relTime, _sz, _n and _uptime —
+// and _uptime floors to whole minutes, so a 33-second cleanup would render as "0m". Same shape the
+// rsync page uses for the same reason; if a third page needs it, that is the point to promote it
+// to the shared file rather than keep a third copy.
+function _dur(s) {
+  if (!s) return '—';
+  const h = Math.floor(s / 3600), m = Math.floor((s % 3600) / 60), sec = s % 60;
+  if (h) return h + 'h ' + m + 'm';
+  if (m) return m + 'm ' + sec + 's';
+  return sec + 's';
+}
+
 // ── Media jobs ────────────────────────────────────────────────────────────────
 // Play state sync, permissions and the cleaner. They work on the same files the arrs manage and
 // appeared in no tab at all — the only way to know whether one had run was to open the Scheduler