Change in API for audio features

[wjakethompson]

Spotify ended access to the audio features end point in November 2024, and the end point is now deprecated. A new API will be needed in order to access audio features. A couple of possible solutions:

• SoundStat: ~0.01€ per track, independent, no third party services.
• ReccoBeats: Free, hard rate limits, appears to depend on Spotify API, so may not be viable long term.