fix: recorder cancel left an empty black screen

mount() adds .rec-root (display:flex) to the overlay element, and that rule sat
after .rec-overlay's display:none — so removing .open didn't hide it. Use
.rec-overlay:not(.open){display:none} to outrank .rec-root by specificity.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lyra/web/static/recorder.css

@@ -7,9 +7,11 @@
   inset: 0;
   z-index: 1000;
   background: var(--bg-dark, #070707);
-  display: none;
   flex-direction: column;
 }
+/* :not(.open) outranks .rec-root's display:flex (added on mount), so closing the
+   overlay actually hides it instead of leaving an empty black screen. */
+.rec-overlay:not(.open) { display: none; }
 .rec-overlay.open { display: flex; }
 
 .rec-root {