fix: remove duplicate site-bg, handle fullscreen promise rejection, unify tooltip language, improve dropdown CSS compat and accessibility

src/components/top-header.tsx

@@ -83,7 +83,7 @@ export async function TopHeader() {
             ) : null}
 
             <details className="relative">
-              <summary className="list-none cursor-pointer flex items-center [&::-webkit-details-marker]:hidden">
+              <summary aria-label="User menu" className="list-none cursor-pointer flex items-center [&::-webkit-details-marker]:hidden">
                 {/* biome-ignore lint/performance/noImgElement: external imager */}
                 <img className="w-[54px] h-[62px] bg-no-repeat bg-center" src={avatar} alt="" />
                 <span className="-ml-2 font-semibold" style={{ color: "var(--color-navbar-text, var(--color-text))" }}>{session.user.name}</span>