fix: replace settings mobile tabs with 2-col grid and remove fab

src/components/app-shell.tsx

@@ -4,7 +4,6 @@ import type { DashboardMeta } from "@/app/d/actions";
 import { Sidebar } from "@/components/sidebar";
 import { Topbar } from "@/components/topbar";
 import { BottomNav } from "@/components/bottom-nav";
-import { Fab } from "@/components/fab";
 import { NavModeProvider } from "@/components/nav-mode-provider";
 
 const BARE_PREFIXES = ["/s/", "/login"];
@@ -38,7 +37,6 @@ export async function AppShell({ signedIn, navStyle, children }: Props) {
         <div className="scroll-area">{children}</div>
       </main>
       <BottomNav />
-      <Fab />
       <NavModeProvider navStyle={navStyle} />
     </div>
   );