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/state/room/markedUnread.test.ts

@@ -46,7 +46,9 @@ test('myMainReceiptPresent: true for a thread_id "main" receipt', () => {
 });
 
 test('myMainReceiptPresent: false for a thread-scoped receipt', () => {
-  const event = receiptEvent({ $abc: { 'm.read': { [ME]: { ts: 1, thread_id: '$root:server' } } } });
+  const event = receiptEvent({
+    $abc: { 'm.read': { [ME]: { ts: 1, thread_id: '$root:server' } } },
+  });
   assert.equal(myMainReceiptPresent(event, ME), false);
 });