fix: css scroll jitter

packages/ui/src/components/session-turn.css

@@ -28,6 +28,7 @@
     align-self: stretch;
     min-width: 0;
     gap: clamp(8px, calc(42px - var(--scroll-y) * 0.48), 42px);
+    overflow-anchor: none;
   }
 
   [data-slot="session-turn-sticky-title"] {