The player's "still alive" flag — every play() is gated on it, so a late one cannot start a detached
<video> after Back — was only ever LOWERED, in an effect's cleanup. React may run a cleanup and mount
again (StrictMode does exactly that in development), and then the flag stayed false for the life of
the player: it never started by itself, and a seek back past the loaded region, which restarts the
session, left it paused. Found on localdev (Westworld S01E06: playing → seek back → the picture
settles, paused). Production does not double-mount, which is why only dev showed it — and why
several earlier localdev measurements "stayed paused".
The effect now raises the flag in its setup. A new test renders the real player under StrictMode and
checks it plays once the media is ready; red without the fix. Verified on localdev: it starts by
itself, and keeps playing through a backward session-restart seek.
peter
f7faa19ee2