srulad-hls worker probe — multi-account verification

Worker hosts under test: ftphls.srulad.net (acct 1) + hls.ftpsrulad.net (acct 2). Each non-iframe URL type is fetched from both hosts and the response inspected. Only URL types backed by publicly-reachable upstream samples are probed — session-bound URLs (mykadri.cc/play.php, expired secvideo1.online tokens, piratedfiles cookied playlists) fail equally on both workers because the upstream is gated, not because the worker is broken. MP4 from videodb.cloud is served as application/octet-stream by the CDN — accepted as valid.