Two bugs addressed in response to Safari changes:
1. Only handle `onEnded` for real streams, preventing `autoNext()` spam when the last track finishes
2. `.play()` is not necessarily a safe operation (if empty wave was started, can cause exception later). Catch this exception and discard it. This also only occurred when playing the last track
* initial idea for playback rate
* Add transparency to dropdown
* Move playback speed component to right controls
* Set mpv speed on startup
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Co-authored-by: jeffvli <jeffvictorli@gmail.com>
