The reported bug: after F, the embed's own fullscreen button is dead. Root cause
measured in Chrome — the browser's fullscreen lock sits on OUR wrapper, so
YouTube's button would need a nested request from a cross-origin frame. Handing
the lock to the iframe fixes it, but `iframe.requestFullscreen()` only resolves
from a CLICK (from a key press the promise stays pending forever, and awaiting
it spends the activation so a fallback is denied too).
So: F keeps fullscreening our wrapper (unchanged, our overlays stay visible) and
a new toolbar button hands the lock to the iframe — verified in real Chrome:
document.fullscreenElement is the IFRAME at 1920x1024, i.e. a plain YouTube
fullscreen where its own controls work.
Round-6 review findings, all fixed:
- one _rate_limiter + one _cancel_poll shared by the yt-dlp hook and run_ffmpeg
(was three hand-rolled throttles; cancel latency differed 2s vs 1s)
- stepVolume takes {delta, fallback} — two adjacent number args were silently
transposable
- volume gestures before the player is ready are honoured instead of dropped
- normalizeVolume's fallback is typed unknown (its guard was unreachable) and
applyVolume takes a number again
- the throttle tests inject a clock instead of patching global time.monotonic
- run_ffmpeg stops the process from ONE exit path (`except BaseException`), so
an exception out of on_progress (a DB write) can no longer orphan a live
ffmpeg after a 10s join on its pipes; _stop is now a no-op on a dead process
- both run_ffmpeg callbacks are throttled to ~1s (they were a DB round-trip per
output line: ~10^5 queries on a long re-encode), mirroring the download hook
- volume arithmetic extracted to lib/playerVolume with unit tests; a corrupt
level now falls back to the LAST GOOD one instead of full blast, and the
sanitising happens where the stored value enters
- RSS is back to two except clauses (the shared tail already sits after the try)
- new tests: callback-exception cleanup, the two throttles; the fake Popen grew
poll() and its wait count is now asserted
Mutation-checked: each new group goes red when its fix is reverted.