Build and push server image / build-and-push (push) Successful in 1m57s
File picker: an optional WebDAV browse root in Settings (User.webdav_base_url) plus a plain-PROPFIND directory listing (webdav_client.list_directory) power a "Browse..." panel on a frame's Whiteboard tab, so a file can be clicked into rather than typing its exact WebDAV URL. Manual URL entry still works unchanged either way. Force-refresh: get_or_refresh_whiteboard takes a force flag that skips the fetch throttle entirely; the Whiteboard tab's refresh button now passes it, so clicking it always re-fetches and re-renders instead of possibly just re-showing the same cached image from within the last ~20 minutes.