develop
Remove deprecated proto fields and unused theme creator code (#13842)
Have server ack app_heartbeat messages received from client (#13810)
Make Default Sidebar Width Configurable (#12154)
![hostframe_app-theme_message_after[chromium].png](/vshmidt/streamlit/content/develop/e2e_playwright/__snapshots__/linux/hostframe_app_test/hostframe_app-theme_message_after%5Bchromium%5D.png){kind=link}
![hostframe_app-theme_message_after[firefox].png](/vshmidt/streamlit/content/develop/e2e_playwright/__snapshots__/linux/hostframe_app_test/hostframe_app-theme_message_after%5Bfirefox%5D.png){kind=link}
![hostframe_app-theme_message_after[webkit].png](/vshmidt/streamlit/content/develop/e2e_playwright/__snapshots__/linux/hostframe_app_test/hostframe_app-theme_message_after%5Bwebkit%5D.png){kind=link}
![hostframe_app-theme_message_before[chromium].png](/vshmidt/streamlit/content/develop/e2e_playwright/__snapshots__/linux/hostframe_app_test/hostframe_app-theme_message_before%5Bchromium%5D.png){kind=link}
![hostframe_app-theme_message_before[firefox].png](/vshmidt/streamlit/content/develop/e2e_playwright/__snapshots__/linux/hostframe_app_test/hostframe_app-theme_message_before%5Bfirefox%5D.png){kind=link}
![hostframe_app-theme_message_before[webkit].png](/vshmidt/streamlit/content/develop/e2e_playwright/__snapshots__/linux/hostframe_app_test/hostframe_app-theme_message_before%5Bwebkit%5D.png){kind=link}
![hostframe_app-toolbar_items[chromium].png](/vshmidt/streamlit/content/develop/e2e_playwright/__snapshots__/linux/hostframe_app_test/hostframe_app-toolbar_items%5Bchromium%5D.png){kind=link}
![hostframe_app-toolbar_items[firefox].png](/vshmidt/streamlit/content/develop/e2e_playwright/__snapshots__/linux/hostframe_app_test/hostframe_app-toolbar_items%5Bfirefox%5D.png){kind=link}
![hostframe_app-toolbar_items[webkit].png](/vshmidt/streamlit/content/develop/e2e_playwright/__snapshots__/linux/hostframe_app_test/hostframe_app-toolbar_items%5Bwebkit%5D.png){kind=link}