[rrvsh]

Summary

MusicGrabber previously ran through manually started transient processes. This adds managed services on Nemesis and Alpha using the packaged MusicGrabber 4.4.3 flake.

Nemesis runs MusicGrabber as the primary user through a NixOS system service. Alpha runs it as a user LaunchAgent. Both reuse the existing writable state and music-library locations, listen on MusicGrabber's loopback default, start automatically, and restart after failed exits.

Both services receive the declarative local slskd URL, completed-download path, shared web credentials and Soulseek enablement. The credentials remain outside the Nix store.

Validation

• nix develop -c just format-nix
• nix develop -c just check-nix
• built and activated the complete Nemesis and Alpha system configurations
• verified the Nemesis system service is enabled, healthy and bound to 127.0.0.1:8080
• verified the Alpha LaunchAgent is loaded, healthy and bound to 127.0.0.1:8080
• verified both services reused their existing state and library paths
• completed live slskd connection tests and Soulseek searches on both hosts
• completed controlled Soulseek download jobs through the persistent service on both hosts
• Nemesis job 8493bfb6: 6 results, completed import
• Alpha job 33611f84: 6 results, completed import