[Feature] Audio service (Deezer integration)

[milospi]

Description

Implement the AudioProvider interface and Deezer-based implementation.
Requirements covered:

Architecture: AudioProvider interface in logic/api
Architecture: Deezer implementation in infra/audio

Acceptance criteria:

AudioProvider interface in logic/api
DeezerAudioProvider in infra/audio
Fetches 30-second previews
Handles playback via LibGDX audio

Related requirement

No response

Architecture layer

None