style: apply prettier across fork files

check:prettier was not part of my gate routine, so formatting drift accumulated
across the session's touched files (and a few older ones). Run prettier --write
to bring the repo back to 'All matched files use Prettier code style!'.
Formatting only — no logic changes. tsc/tests/build all green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/utils/threadList.test.ts

@@ -8,12 +8,12 @@ import {
   ThreadSnapshot,
 } from './threadList';
 
-const t = (
-  id: string,
-  latestTs: number,
-  unread = 0,
-  participated = false,
-): ThreadSnapshot => ({ id, latestTs, unread, participated });
+const t = (id: string, latestTs: number, unread = 0, participated = false): ThreadSnapshot => ({
+  id,
+  latestTs,
+  unread,
+  participated,
+});
 
 test('filterThreads all returns every thread', () => {
   const input = [t('a', 1, 0, false), t('b', 2, 3, true)];