fix: submit question on return key

frontend/src/routes/conversation.$sessionId.tsx

@@ -164,7 +164,13 @@ function RouteComponent() {
             </div>
           </CardContent>
         </Card>
-        <div className="flex gap-3 flex-shrink-0">
+        <form
+          className="flex gap-3 flex-shrink-0"
+          onSubmit={(e) => {
+            e.preventDefault();
+            handleSendQuestion();
+          }}
+        >
           <Input
             className="flex-1"
             placeholder="Start typing..."
@@ -172,14 +178,14 @@ function RouteComponent() {
             onChange={(e) => setInputValue(e.target.value)}
             disabled={isBusy}
           />
-          <Button size="icon" disabled={isBusy} onClick={handleSendQuestion}>
+          <Button size="icon" disabled={isBusy} type="submit">
             {isBusy ? (
               <LoaderCircleIcon className="animate-spin" />
             ) : (
               <SendHorizontalIcon />
             )}
           </Button>
-        </div>
+        </form>
       </div>
     </div>
   );