feat: add Soulseek to the config-aware registry

worker/lyra_worker/registry.py

@@ -1,18 +1,21 @@
+from lyra_worker.adapters._slskd import SlskdClient
 from lyra_worker.adapters._streamrip import StreamripClient
 from lyra_worker.adapters._ytdlp import YtDlpClient
 from lyra_worker.adapters.base import SourceAdapter
 from lyra_worker.adapters.qobuz import QobuzAdapter
+from lyra_worker.adapters.soulseek import SoulseekAdapter
 from lyra_worker.adapters.youtube import YouTubeAdapter
 
 
 def build_adapters(config: dict) -> list[SourceAdapter]:
     """Real source adapters, best-tier first, filtered to those that are configured.
 
-    An adapter is included only if its health() is true (e.g. Qobuz requires
-    credentials in config). Plan 3d adds Soulseek (slskd) the same way.
+    An adapter is included only if its health() is true (Qobuz needs credentials,
+    Soulseek needs an slskd URL + API key). YouTube needs no config.
     """
     candidates: list[SourceAdapter] = [
         QobuzAdapter(StreamripClient(config)),
+        SoulseekAdapter(SlskdClient(config)),
         YouTubeAdapter(YtDlpClient()),
     ]
     return [a for a in candidates if a.health()]