Add broken symlink diagnostics

tests/test_health.py

@@ -2,6 +2,7 @@ from pathlib import Path
 
 from serato_doctor.health import analyze_health
 from serato_doctor.models.crate import Crate, CrateKind
+from serato_doctor.models.filesystem import BrokenSymlink
 from serato_doctor.models.library import Library
 from serato_doctor.models.reference import TrackReference
 from serato_doctor.models.track import DiskTrack
@@ -104,3 +105,16 @@ def test_health_reports_cloud_conflicts_separately_from_exact_duplicates():
     assert report.duplicate_files == 1
     assert report.suspected_cloud_conflict_groups == 1
     assert report.suspected_cloud_conflict_files == 1
+
+
+def test_health_reports_broken_symlinks_without_changing_score():
+    library = Library.build(
+        [reference("Found.mp3")],
+        [track("Found.mp3")],
+        [BrokenSymlink(Path("/music/Broken.mp3"), Path("missing.mp3"))],
+    )
+
+    report = analyze_health(library)
+
+    assert report.score == 100.0
+    assert report.broken_symlinks == 1

tests/test_scanner.py

@@ -1,4 +1,6 @@
-from serato_doctor.scanner import scan_audio
+from pathlib import Path
+
+from serato_doctor.scanner import scan_audio, scan_filesystem
 
 
 def test_scan_audio_finds_supported_files(tmp_path):
@@ -15,3 +17,34 @@ def test_scan_audio_finds_supported_files(tmp_path):
     first = next(track for track in tracks if track.filename == "First.MP3")
     assert first.suffix == ".mp3"
     assert first.size == len(b"synthetic audio")
+
+
+def test_scan_filesystem_reports_broken_symlink(tmp_path):
+    music = tmp_path / "music"
+    music.mkdir()
+    link = music / "Missing.mp3"
+    link.symlink_to("not-there.mp3")
+
+    result = scan_filesystem(music)
+
+    assert result.tracks == ()
+    assert len(result.broken_symlinks) == 1
+    assert result.broken_symlinks[0].path == link
+    assert result.broken_symlinks[0].target == Path("not-there.mp3")
+
+
+def test_valid_audio_symlink_is_scanned_normally(tmp_path):
+    music = tmp_path / "music"
+    music.mkdir()
+    target = music / "Target.mp3"
+    target.write_bytes(b"synthetic audio")
+    link = music / "Linked.mp3"
+    link.symlink_to(target)
+
+    result = scan_filesystem(music)
+
+    assert {track.filename for track in result.tracks} == {
+        "Linked.mp3",
+        "Target.mp3",
+    }
+    assert result.broken_symlinks == ()