feat(notebooks): improve layout responsiveness

- Adjusted `div` class styles to add horizontal scrolling in smaller viewports (`overflow-x-auto`).
- Updated chat column element with additional padding and margin adjustments for better desktop layout.

frontend/src/app/(dashboard)/notebooks/[id]/page.tsx

@@ -119,7 +119,7 @@ export default function NotebookPage() {
           <NotebookHeader notebook={notebook} />
         </div>
 
-        <div className="flex-1 p-6 pt-6 overflow-hidden flex flex-col">
+        <div className="flex-1 p-6 pt-6 overflow-x-auto flex flex-col">
           {/* Mobile: Tabbed interface - only render on mobile to avoid double-mounting */}
           {!isDesktop && (
             <>
@@ -210,7 +210,7 @@ export default function NotebookPage() {
             </div>
 
             {/* Chat Column - always expanded, takes remaining space */}
-            <div className="transition-all duration-150 flex-1">
+            <div className="transition-all duration-150 flex-1 lg:pr-6 lg:-mr-6">
               <ChatColumn
                 notebookId={notebookId}
                 contextSelections={contextSelections}