[ci skip] Fix narrow iframe content and strip anti-debug scripts in proxy

- Remove flex centering from browser-viewer-content; use absolute positioning
  for iframe to fill the entire container
- Strip disable-devtool and devtools-detect script tags from proxied HTML
- Add JS shim hooks to neutralize setInterval-based debugger traps and block
  loading of anti-debug scripts via setAttribute
- Bump image to v1.2.5

modules/kubernetes/f1-stream/files/static/css/custom.css

@@ -1321,9 +1321,6 @@ dialog .dialog-cancel:hover {
   overflow: hidden;
   position: relative;
   background: #000;
-  display: flex;
-  align-items: center;
-  justify-content: center;
   min-height: calc(100vh - 180px);
 }
 
@@ -1335,10 +1332,12 @@ dialog .dialog-cancel:hover {
 }
 
 .browser-iframe {
+  position: absolute;
+  top: 0;
+  left: 0;
   width: 100%;
   height: 100%;
   border: none;
-  flex: 1;
 }
 
 .browser-viewer-content .loading-overlay {