R-563: the remote-backup page polls from a status attribute, and „Fut…" is finally translatable

- backups_remote.html: the status stat carries data-status="{{.Offbox.LastStatus}}"; the poll reads
  v.dataset.status === 'running' instead of v.textContent.indexOf('Fut'). The English page could never
  see a running backup before this (slice 1 shipped the English page with that word left Hungarian).
- The running label becomes {{T "backups_remote.fut"}} — hu „Fut…" unchanged, en „Running…".
- 12 backups_remote parity fixtures re-captured. Proven (audit switch/fixture diff): each differs from
  its predecessor ONLY by the data-status attribute and that one poll line; the other 94 are
  byte-identical. The displayed Hungarian is unchanged.
- Tests: TestR563_PollStartsFromAttribute (hu and en), TestR563_AttributeFollowsTheStatus.
  Red-proofed twice: poll back on textContent → both languages fail; word back inline → the English
  page shows Hungarian.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

controller/internal/web/testdata/i18n_parity/backups_remote_notconf.html

@@ -220,7 +220,10 @@
   var bar  = document.getElementById('offbox-progress-bar');
   var GRACE = 5;              
   var quiet = 0;
-  var sawRunning = (v && v.textContent.indexOf('Fut') >= 0);
+  
+  
+  
+  var sawRunning = (v && v.dataset.status === 'running');
 
   var timer = setInterval(function(){
     fetch('/backup/offbox/status',{headers:{'Accept':'application/json'}})