Fix STREAM toggle: auto-on preview only once per session, manual OFF persists

templates/recounting_upload_lamborghini.html

@@ -430,6 +430,7 @@
 let selectedFile = null;
 let streaming = false;
 let streamUrl = '';
+let previewAutoOn = false;
 let loaded = false;
 let started = false;
 let pendingUploadFile = null;
@@ -735,6 +736,7 @@ async function stopRecount() {
   streaming = false;
   streamUrl = '';
   selectedFile = null;
+  previewAutoOn = false;
   loaded = false;
   started = false;
   batchResultLoaded = false;
@@ -795,6 +797,7 @@ function enablePreview() {
   var img = document.getElementById('stream-img');
   var placeholder = document.getElementById('video-placeholder');
   if (!streamUrl) return;
+  previewAutoOn = true;
   img.onerror = function() {
     if (streaming && streamUrl) {
       img.src = streamUrl + '?' + Date.now();
@@ -827,15 +830,17 @@ function applyState(data) {
     document.getElementById('video-status').innerHTML =
       '<span style="width:5px;height:5px;background:var(--success);display:inline-block;"></span> streaming ' + (data.file_name || '');
     document.getElementById('video-status').className = 'video-status connected';
-    enablePreview();
+    if (!previewAutoOn) enablePreview();
 
     loadBatchResult(data.file);
   } else if (data.file && selectedFile === data.file) {
+    previewAutoOn = false;
     loaded = false;
     started = false;
     renderButtons();
     loadBatchResult(data.file);
   } else if (!data.streaming) {
+    previewAutoOn = false;
     loaded = false;
     started = false;
     renderButtons();