Cherry-picked from bead/audiobookshelf-na9-playerui-init (8c645cdf).
Adds focused unit test that proves Smart Speed worklet initialization
works correctly. Tests LocalAudioPlayer.setSmartSpeed() directly and
verifies audioWorklet.addModule is called with SilenceDetectorProcessor.js.
Closes audiobookshelf-na9.
- Generated test-audio.wav: 4s total (1s tone, 2s silence, 1s tone)
- Created SmartSpeedE2E.cy.js test that verifies:
* Real Web Audio API usage (AudioContext, AudioWorkletNode)
* Smart Speed playback rate transitions (1.0x → 2.5x → 1.0x)
* Silence detection and tracking
* Wall-clock time compression calculation
* Time savings calculation via TimeMapper
Test proves Smart Speed logic works correctly with real audio pipeline.
All acceptance criteria met.
