VOOMI audio attribution

Original recording: Dodge 318 V8 exhaust
Creator: BoilingSand
Source: https://freesound.org/people/BoilingSand/sounds/49988/
License: Creative Commons Attribution 3.0 Unported (CC BY 3.0)
License URL: https://creativecommons.org/licenses/by/3.0/

Changes: The recording was edited into phase-aligned, seam-crossfaded,
level-balanced power and coast loops, plus a starting excerpt, for
interactive engine playback. RPM is estimated from exhaust periodicity.
Sport mode bypasses a simulated muffler. PCM files are derived from
the available HQ MP3, not the original lossless WAV.

The same source and license information is included in manifest.json.