fix: server.proxy.target이 VITE_PROXY_TARGET을 참조하도록 수정

Author: kanghaeun

vite.config.ts

@@ -20,7 +20,7 @@ export default ({ mode }: ConfigEnv) => {
     server: {
       proxy: {
         '/api': {
-          target: env.VITE_API_BASE_URL,
+          target: env.VITE_PROXY_TARGET,
           changeOrigin: true,
           secure: false,
         },