fix: corner-smoothing 잘못된 값 사용 수정

Author: 2skydev

src/renderer/src/styles/utils.css

@@ -1,5 +1,5 @@
 @theme inline {
-  --corner-smoothing-size-system-ui: 'system-ui';
+  --corner-smoothing-size-system-ui: system-ui;
   --corner-smoothing-size-none: 0%;
   --corner-smoothing-size-sm: 30%;
   --corner-smoothing-size-md: 60%;