Add album-aware track matching for multi-artist albums

When artist-specific track search fails, falls back to album-aware
matching: finds the album by title (any artist), then checks if the
track exists on it. Fixes daily re-downloads of collaborative albums
filed under a different artist (e.g., "Spiral Staircases" tagged
under "The Alchemist" but scanned from "Larry June's" watchlist).

- check_track_exists: new album parameter, album-aware fallback with
  0.8 album title threshold + 0.7 track title threshold
- Watchlist scanner: passes album_data.get('name') to track checks
- Download modal: passes batch_album_context to fallback track search
- Wishlist callers (4 spots): extract and pass track album name
- Backwards compatible: album=None default, no change for callers
  without album context (singles, playlists)

core/watchlist_scanner.py

@@ -779,7 +779,7 @@ class WatchlistScanner:
                         if not self._should_include_track(track, album_data, watchlist_artist):
                             continue  # Skip this track based on content type preferences
 
-                        if self.is_track_missing_from_library(track):
+                        if self.is_track_missing_from_library(track, album_name=album_data.get('name')):
                             new_tracks_found += 1
 
                             # Add to wishlist
@@ -1337,9 +1337,9 @@ class WatchlistScanner:
             logger.warning(f"Error checking track content type inclusion: {e}")
             return True  # Default to including on error
 
-    def is_track_missing_from_library(self, track) -> bool:
+    def is_track_missing_from_library(self, track, album_name: str = None) -> bool:
         """
-        Check if a track is missing from the local Plex library.
+        Check if a track is missing from the local library.
         Uses the same matching logic as the download missing tracks modals.
         """
         try:
@@ -1374,7 +1374,7 @@ class WatchlistScanner:
                     # Use same database check as modals with server awareness
                     from config.settings import config_manager
                     active_server = config_manager.get_active_media_server()
-                    db_track, confidence = self.database.check_track_exists(query_title, artist_name, confidence_threshold=0.7, server_source=active_server)
+                    db_track, confidence = self.database.check_track_exists(query_title, artist_name, confidence_threshold=0.7, server_source=active_server, album=album_name)
                     
                     if db_track and confidence >= 0.7:
                         logger.debug(f"✔️ Track found in library: '{original_title}' by '{artist_name}' (confidence: {confidence:.2f})")

database/music_database.py

@@ -4830,10 +4830,13 @@ class MusicDatabase:
             return list(set(variations))
 
     
-    def check_track_exists(self, title: str, artist: str, confidence_threshold: float = 0.8, server_source: str = None) -> Tuple[Optional[DatabaseTrack], float]:
+    def check_track_exists(self, title: str, artist: str, confidence_threshold: float = 0.8, server_source: str = None, album: str = None) -> Tuple[Optional[DatabaseTrack], float]:
         """
         Check if a track exists in the database with enhanced fuzzy matching and confidence scoring.
-        Now uses the same sophisticated matching approach as album checking for consistency.
+
+        Args:
+            album: Optional album name — enables album-aware matching for multi-artist albums
+
         Returns (track, confidence) tuple where confidence is 0.0-1.0
         """
         try:
@@ -4873,9 +4876,57 @@ class MusicDatabase:
             if best_match and best_confidence >= confidence_threshold:
                 logger.debug(f"✅ Enhanced track match found: '{title}' -> '{best_match.title}' (confidence: {best_confidence:.3f})")
                 return best_match, best_confidence
-            else:
+
-                logger.debug(f"❌ No confident track match for '{title}' (best: {best_confidence:.3f}, threshold: {confidence_threshold})")
+            # Album-aware fallback: find album by title (any artist), check tracks on it
-                return None, best_confidence
+            # Handles multi-artist albums filed under a different artist in the library
+            if album and best_confidence < confidence_threshold:
+                logger.debug(f"⚠️ Artist-specific search failed, trying album-aware fallback: '{title}' on '{album}'")
+                try:
+                    album_candidates = self.search_albums(title=album, artist="", limit=10, server_source=server_source)
+                    for album_candidate in album_candidates:
+                        album_title_sim = max(
+                            self._string_similarity(self._normalize_for_comparison(album), self._normalize_for_comparison(album_candidate.title)),
+                            self._string_similarity(self._clean_album_title_for_comparison(album), self._clean_album_title_for_comparison(album_candidate.title))
+                        )
+                        if album_title_sim < 0.8:
+                            continue
+
+                        conn = self._get_connection()
+                        cursor = conn.cursor()
+                        source_filter = "AND t.server_source = ?" if server_source else ""
+                        params = [album_candidate.id] + ([server_source] if server_source else [])
+                        cursor.execute(f"""
+                            SELECT t.*, a.name as artist_name, al.title as album_title
+                            FROM tracks t
+                            JOIN artists a ON a.id = t.artist_id
+                            JOIN albums al ON al.id = t.album_id
+                            WHERE t.album_id = ? {source_filter}
+                        """, params)
+
+                        for row in cursor.fetchall():
+                            db_track = DatabaseTrack(
+                                id=row['id'], title=row['title'], artist_name=row['artist_name'],
+                                album_title=row['album_title'], album_id=row['album_id'],
+                                track_number=row['track_number'], duration=row['duration'],
+                                file_path=row['file_path'], bitrate=row['bitrate'],
+                                artist_id=row['artist_id'], server_source=row['server_source']
+                            )
+                            title_sim = max(
+                                self._string_similarity(self._normalize_for_comparison(title), self._normalize_for_comparison(db_track.title)),
+                                self._string_similarity(self._clean_track_title_for_comparison(title), self._clean_track_title_for_comparison(db_track.title))
+                            )
+                            if title_sim > best_confidence and title_sim >= 0.7:
+                                best_confidence = title_sim
+                                best_match = db_track
+
+                        if best_match and best_confidence >= 0.7:
+                            logger.debug(f"✅ Album-aware fallback matched: '{title}' on '{album}' -> '{best_match.title}' by '{best_match.artist_name}' (title_sim: {best_confidence:.3f})")
+                            return best_match, best_confidence
+                except Exception as album_fallback_err:
+                    logger.debug(f"Album-aware fallback error: {album_fallback_err}")
+
+            logger.debug(f"❌ No confident track match for '{title}' (best: {best_confidence:.3f}, threshold: {confidence_threshold})")
+            return None, best_confidence
             
         except Exception as e:
             logger.error(f"Error checking track existence for '{title}' by '{artist}': {e}")

web_server.py

@@ -18584,6 +18584,7 @@ def _automatic_wishlist_cleanup_after_db_update():
             track_name = track.get('name', '')
             artists = track.get('artists', [])
             spotify_track_id = track.get('spotify_track_id') or track.get('id')
+            track_album = track.get('album', {}).get('name') if isinstance(track.get('album'), dict) else track.get('album')
 
             # Skip if no essential data
             if not track_name or not artists or not spotify_track_id:
@@ -18604,7 +18605,8 @@ def _automatic_wishlist_cleanup_after_db_update():
                     db_track, confidence = db.check_track_exists(
                         track_name, artist_name,
                         confidence_threshold=0.7,
-                        server_source=active_server
+                        server_source=active_server,
+                        album=track_album
                     )
                     
                     if db_track and confidence >= 0.7:
@@ -19786,6 +19788,7 @@ def _process_wishlist_automatically(automation_id=None):
                 track_name = track.get('name', '')
                 artists = track.get('artists', [])
                 spotify_track_id = track.get('spotify_track_id') or track.get('id')
+                track_album = track.get('album', {}).get('name') if isinstance(track.get('album'), dict) else track.get('album')
 
                 if not track_name or not artists or not spotify_track_id:
                     continue
@@ -19804,7 +19807,8 @@ def _process_wishlist_automatically(automation_id=None):
                         db_track, confidence = db.check_track_exists(
                             track_name, artist_name,
                             confidence_threshold=0.7,
-                            server_source=active_server
+                            server_source=active_server,
+                            album=track_album
                         )
 
                         if db_track and confidence >= 0.7:
@@ -20658,6 +20662,7 @@ def start_wishlist_missing_downloads():
             track_name = track.get('name', '')
             artists = track.get('artists', [])
             spotify_track_id = track.get('spotify_track_id') or track.get('id')
+            track_album = track.get('album', {}).get('name') if isinstance(track.get('album'), dict) else track.get('album')
 
             if not track_name or not artists or not spotify_track_id:
                 continue
@@ -20676,7 +20681,8 @@ def start_wishlist_missing_downloads():
                     db_track, confidence = db.check_track_exists(
                         track_name, artist_name,
                         confidence_threshold=0.7,
-                        server_source=active_server
+                        server_source=active_server,
+                        album=track_album
                     )
 
                     if db_track and confidence >= 0.7:
@@ -20890,6 +20896,7 @@ def cleanup_wishlist():
             track_name = track.get('name', '')
             artists = track.get('artists', [])
             spotify_track_id = track.get('spotify_track_id') or track.get('id')
+            track_album = track.get('album', {}).get('name') if isinstance(track.get('album'), dict) else track.get('album')
 
             # Skip if no essential data
             if not track_name or not artists or not spotify_track_id:
@@ -20912,7 +20919,8 @@ def cleanup_wishlist():
                     db_track, confidence = db.check_track_exists(
                         track_name, artist_name,
                         confidence_threshold=0.7,
-                        server_source=active_server
+                        server_source=active_server,
+                        album=track_album
                     )
                     
                     if db_track and confidence >= 0.7:
@@ -23324,6 +23332,7 @@ def _run_full_missing_tracks_process(batch_id, playlist_id, tracks_json):
                         found, confidence = True, best_sim
                     else:
                         # Fall back to global per-track search for this track
+                        _fallback_album = batch_album_context.get('name') if batch_album_context else None
                         for artist in artists:
                             if isinstance(artist, str):
                                 artist_name = artist
@@ -23332,7 +23341,7 @@ def _run_full_missing_tracks_process(batch_id, playlist_id, tracks_json):
                             else:
                                 artist_name = str(artist)
                             db_track, track_confidence = db.check_track_exists(
-                                track_name, artist_name, confidence_threshold=0.7, server_source=active_server
+                                track_name, artist_name, confidence_threshold=0.7, server_source=active_server, album=_fallback_album
                             )
                             if db_track and track_confidence >= 0.7:
                                 found, confidence = True, track_confidence