Spotify streaming not working with Traktor Pro 4.4.x on macOS Tahoe

[mat6603]

*Environment:

• Traktor Pro 4.4.122
• macOS Tahoe 26.1 (Apple Silicon)
• traktor-streaming-proxy v0.5.2
• Java Temurin 25
• ffmpeg installed

*Problem:
YouTube streaming works perfectly, but Spotify tracks fail with "Download / network error" in Traktor.

*Log shows:

• Spotify authentication successful (Authenticated as ...)
• /v4/catalog/genres/ returns Spotify and YouTube correctly
• YouTube download works: 200 OK: GET - /v4/catalog/tracks/923680705881910307/download/
• Spotify fails: 404 Not Found: GET - /v4/catalog/tracks/ (no track ID)

It appears Traktor 4 requests /v4/catalog/tracks/ without a track ID for Spotify, which returns 404.

*Steps to reproduce:

1. Configure proxy with sources.enabled=spotify,youtube
2. Authenticate Spotify successfully
3. Load YouTube track → works
4. Load Spotify track from "My Playlists" or search → network error

*Expected:
Spotify tracks should download like YouTube tracks.

[0xf4b1]

This is likely #52 and you need spotify premium