Ad-block annoyance lists (e.g. Brave Shields) hide floating corner buttons via attribute
selectors like [aria-label="Back to top"] / [title=...]. Drop both attributes and provide the
accessible name with a visually-hidden child span instead, which those selectors can't match.
A reusable BackToTop fades in once the active page's <main> is scrolled past ~600px and
smooth-scrolls it back to the top. Rendered once at the App root, portaled to <body> for
viewport-fixed placement (bottom-right, below the chat dock), and re-binds to the live <main> on
navigation (page or channel change) so it works on every scrollable page incl. the channel page.
EN/HU/DE.
peter