paramètres: fix logs Copier button scrolling out of view on horizontal scroll

Wrap .log-output and the copy button in a .log-output-wrapper div
with position:relative, so the button sits outside the overflow-x:auto
scroll container and stays fixed at the top-right corner.

TODO.md

@@ -2,3 +2,4 @@
 
 - [x] Fix CSP: add `frame-src` to allow iframes from `videos.erg.be` and `depnum.happyngreen.fr`
 - [x] Website iframe overlay: remove blur, move button to bottom-right, replace text with SVG icon + tooltip
+- [x] Fix "Copier" button in logs section scrolling out of view on horizontal scroll