refactor: fix scroll to last user query ux

- Updated DashboardClientLayout to improve child component overflow handling.
- Refactored NewChatPage to streamline the layout and integrate ChatHeader directly within the Thread component.
- Added optional header prop to Thread component for better customization.
- Cleaned up ChatHeader by removing unnecessary wrapper for improved design.

surfsense_web/app/dashboard/[search_space_id]/client-layout.tsx

@@ -265,7 +265,7 @@ export function DashboardClientLayout({
 							</div>
 						</div>
 					</header>
-					<div className="grow flex-1 overflow-auto min-h-[calc(100vh-64px)]">{children}</div>
+					<div className="flex-1 overflow-hidden">{children}</div>
 				</main>
 			</SidebarInset>
 		</SidebarProvider>

surfsense_web/app/dashboard/[search_space_id]/new-chat/[[...chat_id]]/page.tsx

@@ -626,11 +626,11 @@ export default function NewChatPage() {
 			<LinkPreviewToolUI />
 			<DisplayImageToolUI />
 			<ScrapeWebpageToolUI />
-			<div className="flex flex-col h-[calc(100vh-64px)] max-h-[calc(100vh-64px)] overflow-hidden">
-				<ChatHeader searchSpaceId={searchSpaceId} />
-				<div className="flex-1 min-h-0 overflow-hidden">
-					<Thread messageThinkingSteps={messageThinkingSteps} />
-				</div>
+			<div className="flex flex-col h-[calc(100vh-64px)] overflow-hidden">
+				<Thread
+					messageThinkingSteps={messageThinkingSteps}
+					header={<ChatHeader searchSpaceId={searchSpaceId} />}
+				/>
 			</div>
 		</AssistantRuntimeProvider>
 	);