Add per-track artist to filename: 09_Titel_-_Kuenstler.flac

- Track model: add optional artist field (None = fall back to album artist)
- organizer: append _-_<artist> to each filename
- tagger: use track.artist over album.artist for the 'artist' tag
- playlist: widen glob pattern to match new _-_<artist> suffix
- tests: update assertions + add test for track-artist override

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/musiksammlung/models.py

@@ -10,6 +10,7 @@ from pydantic import BaseModel, field_validator
 class Track(BaseModel):
     track_number: int
     title: str
+    artist: str | None = None  # Track-Künstler (z.B. bei Samplern); None = Album-Künstler
 
 
 class Disc(BaseModel):

src/musiksammlung/organizer.py

@@ -131,7 +131,8 @@ def build_mapping(
 
         for audio_file, track in zip(audio_files, disc.tracks):
             safe_title = _sanitize_filename(track.title)
-            new_name = f"{track.track_number:02d}_{safe_title}{audio_file.suffix}"
+            safe_artist = _sanitize_filename(track.artist or album.artist)
+            new_name = f"{track.track_number:02d}_{safe_title}_-_{safe_artist}{audio_file.suffix}"
             mapping[audio_file] = target_dir / new_name
 
     return mapping

src/musiksammlung/playlist.py

@@ -35,7 +35,7 @@ def generate_playlist(album: Album, album_dir: Path) -> Path:
         for track in disc.tracks:
             safe_title = _sanitize_filename(track.title)
             # Audiodatei im Zielverzeichnis finden
-            pattern = f"{track.track_number:02d}_{safe_title}.*"
+            pattern = f"{track.track_number:02d}_{safe_title}*"
             if multi_disc:
                 search_dir = album_dir / f"CD{disc.disc_number}"
             else:

src/musiksammlung/tagger.py

@@ -29,7 +29,7 @@ def tag_file(
         logger.warning("Kann Datei nicht öffnen: %s", path)
         return
 
-    audio["artist"] = album.artist
+    audio["artist"] = track.artist or album.artist
     audio["album"] = album.album
     audio["albumartist"] = album.artist
     audio["title"] = track.title