feat(hero): add disconnect icon next to headline

PhoneOff icon inline after the hero line — visual pun on "phone home".
Muted text-neutral-500, 0.75em-sized so it scales with the headline
and doesn't dominate.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: lx-0

src/components/pages/ChatShell.tsx

@@ -6,6 +6,7 @@ import { useLlmStore } from "@/lib/llm-store.ts";
 import { preloadFileset } from "@/lib/mediapipe-llm.ts";
 import { MODEL_CATALOG, type ModelId } from "@/lib/model-catalog.ts";
 import { AssistantRuntimeProvider } from "@assistant-ui/react";
+import { PhoneOff } from "lucide-react";
 import { useEffect, useState } from "react";
 import { Tagline } from "../atoms/Tagline.tsx";
 import {
@@ -76,6 +77,10 @@ export function ChatShell() {
             <div className="mx-auto flex w-full max-w-md flex-1 flex-col gap-6 px-4 py-8">
               <h1 className="text-center text-xl font-medium leading-snug tracking-tight text-neutral-100 text-balance sm:text-2xl">
                 {t("hero.headline")}
+                <PhoneOff
+                  aria-hidden="true"
+                  className="ml-2 inline-block h-[0.75em] w-[0.75em] align-baseline text-neutral-500"
+                />
               </h1>
               {caps && cached && state.kind === "idle" && (
                 <ModelPicker selectedId={picker} onSelect={setPicker} caps={caps} cached={cached} />