add more accurate data retention message

frontend/src/App.js

@@ -118,9 +118,7 @@ function App() {
                 mx: "auto",
               }}
             >
-              We keep processed documents for research purposes, to which you
-              agree by using the space. For a fully private usage, please
-              duplicate the advanced space
+              We may retain processed documents processed in this space for safety purposes for up to 30 days. For maximum privacy with zero data retention, you are encouraged to duplicate the space to your own huggingface organization.
             </Box>
           </Box>
         </Container>