feat: Tagger seam and pipeline tag-stage integration

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

worker/lyra_worker/pipeline.py

@@ -103,6 +103,7 @@ def run_pipeline(
     job_id: str,
     adapters: Sequence[SourceAdapter],
     resolver=None,
+    tagger=None,
     min_confidence: float = 0.7,
     dest_root: str = "/music",
 ) -> None:
@@ -174,6 +175,12 @@ def run_pipeline(
         _fail(conn, job_id, "incomplete download")
         return
 
+    if tagger is not None:
+        try:
+            tagger.tag_album(dest, target)
+        except Exception as e:  # a tagging failure must not discard a good download
+            print(f"pipeline: tagging failed for job {job_id}: {e}", flush=True)
+
     # 6. import
     _set_state(conn, job_id, "imported", "import")
     _import(conn, job_id, target, winner, result.path or dest)

worker/lyra_worker/tagger.py

@@ -0,0 +1,9 @@
+from typing import Protocol
+
+from lyra_worker.types import MBTarget
+
+
+class Tagger(Protocol):
+    def tag_album(self, album_dir: str, target: MBTarget) -> None:
+        """Tag the album's audio files with target's metadata and rename them."""
+        ...

worker/lyra_worker/types.py

@@ -8,6 +8,7 @@ class MBTarget:
     track_count: int | None = None
     total_duration_s: int | None = None
     year: int | None = None
+    tracklist: tuple[str, ...] = ()
 
 
 @dataclass(frozen=True)