fix: constrain session transcript height

frontend/src/pages/session-memory/view.tsx

@@ -123,7 +123,12 @@ function TranscriptConversation({ value }: { value?: string }) {
   }
 
   return (
-    <div className='space-y-3'>
+    <div
+      aria-label='Session transcript'
+      className='max-h-[32rem] space-y-3 overflow-y-auto overscroll-contain pr-2 focus:outline-none focus:ring-2 focus:ring-[#35b7a5]/30 lg:max-h-[calc(100vh-18rem)]'
+      data-testid='session-transcript-scroll'
+      tabIndex={0}
+    >
       {turns.map((turn, index) => (
         <div
           key={`${turn.speaker}-${index}-${turn.text.slice(0, 18)}`}