Built only viewer in lowcoder-sdk.

Author: Imiss-U1025

client/packages/lowcoder-sdk/src/dev-utils/buildVars.js

@@ -55,4 +55,8 @@ export const buildVars = [
     name: "REACT_APP_DISABLE_JS_SANDBOX",
     defaultValue: "",
   },
+  {
+    name: "REACT_APP_VIEW_MODE",
+    defaultValue: "admin"
+  }
 ];