Website: Next.js app for accounts, linking, who's online, device sign-in and the console

apps/web: Next.js 16 (App Router), Tailwind 4 and shadcn/ui, light and dark from the system. Pages render on the
server and call the API with Eden Treaty (typed by @t5de/api), forwarding the visitor's cookie; forms use server
actions; sign-up, sign-in and sign-out use Better Auth's React client. /api is rewritten to the API so its cookies
are first-party. Who's online follows the API's event stream (Next's gzip is off: it held the stream back).
Standalone output with a Dockerfile; deploys to Vercel as is.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

apps/web/app/account/link-settings.tsx

@@ -0,0 +1,35 @@
+"use client";
+// A linked account's two settings, saved as soon as they're switched.
+import { useOptimistic, useState, useTransition } from "react";
+import { FormMessage } from "@/components/forms";
+import { Switch } from "@/components/ui/switch";
+import type { ActionState } from "@/lib/actions";
+import { saveSettings } from "./actions";
+
+type Settings = { showBadge: boolean; showPresence: boolean };
+
+export function LinkSettings({ imvuId, ...saved }: Settings & { imvuId: number }) {
+  const [settings, setOptimistic] = useOptimistic(saved);
+  const [state, setState] = useState<ActionState>(null);
+  const [pending, startTransition] = useTransition();
+
+  const change = (key: keyof Settings) => (value: boolean) =>
+    startTransition(async () => {
+      setOptimistic({ ...settings, [key]: value });
+      setState(await saveSettings(imvuId, { [key]: value }));
+    });
+
+  return (
+    <div className="space-y-3">
+      <label className="flex items-center gap-3 text-sm">
+        <Switch checked={settings.showBadge} onCheckedChange={change("showBadge")} disabled={pending} />
+        Show T5DE badge
+      </label>
+      <label className="flex items-center gap-3 text-sm">
+        <Switch checked={settings.showPresence} onCheckedChange={change("showPresence")} disabled={pending} />
+        Show when I&apos;m online in T5DE
+      </label>
+      <FormMessage state={state} />
+    </div>
+  );
+}