chore: prettier format all files, brotli, Sentry release tagging, CI gates

Prettier: auto-formatted 103 files to fix baseline. Prettier check in CI
  is now a hard gate (removed continue-on-error).

Brotli: installed libnginx-mod-http-brotli-filter/static. Enabled in nginx
  with brotli_static on for pre-compressed assets and comp_level 6.

Sentry releases: deploy script now exports VITE_APP_VERSION=<git-short-sha>
  before building so each Sentry release maps to an exact commit.
  CI also passes github.sha as VITE_APP_VERSION.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/features/lobby/LobbyHero.tsx

@@ -22,7 +22,9 @@ export function LobbyHero() {
   const name = useRoomName(space);
   const topic = useRoomTopic(space);
   const avatarMxc = useRoomAvatar(space);
-  const avatarUrl = avatarMxc ? mxcUrlToHttp(mx, avatarMxc, useAuthentication, 96, 96, 'crop') ?? undefined : undefined;
+  const avatarUrl = avatarMxc
+    ? mxcUrlToHttp(mx, avatarMxc, useAuthentication, 96, 96, 'crop') ?? undefined
+    : undefined;
 
   return (
     <PageHero