Improve chat navigation, model selection, and streaming

components/ai-elements/code-block.tsx

@@ -2,7 +2,7 @@
 
 import { Button } from "@/components/ui/button";
 import { cn } from "@/lib/utils";
-import { CheckIcon, CopyIcon } from "lucide-react";
+import { RiCheckLine, RiFileCopyLine } from "@remixicon/react";
 import {
   type ComponentProps,
   createContext,
@@ -162,7 +162,7 @@ export const CodeBlockCopyButton = ({
     }
   };
 
-  const Icon = isCopied ? CheckIcon : CopyIcon;
+  const Icon = isCopied ? RiCheckLine : RiFileCopyLine;
 
   return (
     <Button