chore: clean up placeholder comments and over-engineering

app/(order)/orders/page.tsx

@@ -104,14 +104,16 @@ export default function OrderListPage() {
                       {order.status === "in_progress" &&
                         (() => {
                           const session = mockChatSessions.find((s) => s.orderId === order.id)
-                          return session ? (
-                            <Button variant="outline" size="sm" asChild>
-                              <Link href={`/chat/${session.id}`}>
-                                <MessageSquare className="mr-1 h-3.5 w-3.5" />
-                                聊天
-                              </Link>
-                            </Button>
-                          ) : null
+                          return (
+                            session && (
+                              <Button variant="outline" size="sm" asChild>
+                                <Link href={`/chat/${session.id}`}>
+                                  <MessageSquare className="mr-1 h-3.5 w-3.5" />
+                                  聊天
+                                </Link>
+                              </Button>
+                            )
+                          )
                         })()}
                       {order.status === "completed" && (
                         <Button variant="outline" size="sm">