Make a complete VOD reach native `ended` (and loop) reliably even when audio
and video tracks end a few ms apart:
1. `end-of-stream` reactor gains LAST_SEGMENT_REACHED_SLACK (0.5s) on the
"playhead reached the last segment" gate — a tiny final segment plus Chrome's
audio-clock freeze otherwise deadlocks endOfStream().
2. New `recover-end-stall` behavior: on `waiting`, if the MediaSource is
'ended' and the playhead is within endStallNudgeWindow (0.2s) of the
reachable buffered end (getMinBufferedEnd over the SourceBuffers), nudge
currentTime = duration to force native ended. Event-driven; inert for
live / clean-ending streams.
ADR: internal/decisions/end-of-stream-av-skew-recovery.md
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
