Frames are captured on the Pi and downscaled to 480 px (~20–40 KB every 3 s). Nothing is captured while this is off, and the request expires by itself if you close the page.
The file is sent straight to the device over MQTT in 48 KB chunks — no third-party host, nothing public, and no link to expire. It works from a file:// page, which a browser upload to an external host does not (Chromium blocks that as blocked:origin).
Photos use the playlist's seconds-per-tab.
Videos always play to completion — the device watches the
player and advances when the clip ends, so no dwell is needed.
Up to 512 MB per file.
Pushing takes the whole queue, keeps it on screen as a batch, and empties the queue — so the same announcement can't go out twice by accident. The batch is saved on the device, so a restart mid-run picks it back up.
A one-off disables itself after it fires. Scheduled runs send whatever is in the queue at that moment and leave the queue in place, so a weekly window keeps working.