test(home): follow the profile hook's return through the signOut marker

The mount-once bootstrap effect keeps its literal `}, []);` dependency array:
two existing contract tests use that exact text as a slicing landmark, so the
effect stays as it was and its existing exhaustive-deps warning simply names two
more stable setters. Only the signOut slice marker in
chat-navigation-a11y-contract moves, with the three-column note; the assertion's
subject is untouched.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JUei7K13cYxLHE3Axe4A45

frontend/src/app/page.tsx

@@ -1098,7 +1098,7 @@ export default function Home() {
       window.clearTimeout(bootstrapTimeout);
       controller.abort();
     };
-  }, [setProfile, setProfileDraft]);
+  }, []);
 
   useEffect(() => {
     if (!hydrated || uiPreview.current) return;

frontend/tests/chat-navigation-a11y-contract.test.ts

@@ -76,7 +76,12 @@ test("auth redirects stay hard document loads so stale session state cannot surv
   assert.doesNotMatch(pageSource, /router\.replace\("\/login"\)/);
 
   // And: the login redirect after sign-out drops the whole React tree with the session.
-  const signOut = sourceBetween(pageSource, "async function signOut()", "return {\n    refreshAccount,");
+  // 原值: sourceBetween(..., "async function signOut()", "return {\n    refreshAccount,")
+  // 新值: 同一起点，终点改成 "return {\n    profile,"
+  // 原因: 状态下沉第二批把六个 profile 状态搬进 use-profile-onboarding.ts，hook 的
+  //       return 现在以 profile 开头，refreshAccount 不再是第一个字段。切的还是
+  //       signOut 函数体，断言主语（退出后硬跳 /login）一字未改。
+  const signOut = sourceBetween(pageSource, "async function signOut()", "return {\n    profile,");
   assert.match(signOut, /await selfHostedOtpActions\.signOut\(\);\n\s*window\.location\.assign\("\/login"\)/);
 
   // And: the billing pane keeps the same 401 precedent without a dedicated membership page.