fix(ai-chat): cast the history panel shadow only when open so it stops bleeding a dark sliver onto the right edge while closed

src/app/features/bots/BotConversations.css.ts

@@ -69,11 +69,17 @@ export const History = style({
   flexDirection: 'column',
   backgroundColor: color.Surface.Container,
   borderLeft: `${config.borderWidth.B300} solid ${color.Surface.ContainerLine}`,
-  boxShadow: '-12px 0 40px rgba(0, 0, 0, 0.32)',
   transform: 'translateX(100%)',
   transition: 'transform 220ms cubic-bezier(0.22, 1, 0.36, 1)',
   selectors: {
-    '&[data-open]': { transform: 'translateX(0)' },
+    // Shadow ONLY when open. The base `translateX(100%)` parks the panel off the right edge, but its
+    // cast shadow (offset -12px, i.e. leftward, + 40px blur) reaches back INTO the body and Body's
+    // `overflow: hidden` can't clip it (the leak lands inside the box, not past its edge) — so a base
+    // shadow paints a dark sliver on the right edge even while the drawer is closed.
+    '&[data-open]': {
+      transform: 'translateX(0)',
+      boxShadow: '-12px 0 40px rgba(0, 0, 0, 0.32)',
+    },
   },
   '@media': {
     '(prefers-reduced-motion: reduce)': { transition: 'none' },