Lay the party logo over the background

Centred, spanning 60% of the screen width, on the poster's layer so the
video frame and the stills still pass in front of it. The file lives in
assets/ with the posters, so it has to be kept out of the background
rotation — it is the one image there that is never a background.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H9v2Xoa6eoeGYpK6gp95k9

public/player/player.js

@@ -2,7 +2,7 @@ import { connect } from '/shared/socket.js';
 import { OVERLAP_SECONDS, HARD_CUT_SECONDS, AUTO_BACKGROUND, AUTO_ANIMATION } from '/config.js';
 import { createPlayer, loadApi, STATE } from './yt.js';
 import { startAnimationCycle } from './motion.js';
-import { startBackgroundCycle } from './backdrop.js';
+import { startBackgroundCycle, showLogo } from './backdrop.js';
 import { requestCapture } from './capture.js';
 
 const TICK_MS = 250;
@@ -25,6 +25,8 @@ const backgrounds = startBackgroundCycle(
   state.background,
 );
 
+showLogo(document.getElementById('logo'));
+
 // --- start gate ---------------------------------------------------------
 
 const gate = document.getElementById('gate');