Preserve track provenance through lossy transcoding (#245)

- Update provenance file_path when Blasphemy Mode deletes the original
  FLAC and replaces it with a lossy copy — provenance now points to
  the transcoded file instead of the deleted original
- New update_provenance_file_path() database method
- Non-blocking: wrapped in try/except, never interrupts transcode flow
- Downsample (hi-res → CD quality) is unaffected — replaces in-place
  with same filename, provenance stays valid

database/music_database.py

@@ -8667,6 +8667,20 @@ class MusicDatabase:
             logger.error(f"Error getting track downloads: {e}")
             return []
 
+    def update_provenance_file_path(self, old_path: str, new_path: str) -> bool:
+        """Update file_path in provenance records when a file is transcoded/moved."""
+        try:
+            conn = self._get_connection()
+            cursor = conn.cursor()
+            cursor.execute("""
+                UPDATE track_downloads SET file_path = ? WHERE file_path = ?
+            """, (new_path, old_path))
+            conn.commit()
+            return cursor.rowcount > 0
+        except Exception as e:
+            logger.error(f"Error updating provenance file path: {e}")
+            return False
+
     def get_download_by_file_path(self, file_path: str) -> Optional[dict]:
         """Find the most recent download record for a file path."""
         try:

web_server.py

@@ -16520,6 +16520,12 @@ def _create_lossy_copy(final_path):
                         from mutagen import File as MutagenFile
                         test_audio = MutagenFile(out_path)
                         if test_audio is not None:
+                            # Update provenance record to point to the new transcoded file
+                            try:
+                                db = get_database()
+                                db.update_provenance_file_path(final_path, out_path)
+                            except Exception:
+                                pass
                             os.remove(final_path)
                             print(f"🔥 [Blasphemy Mode] Deleted original: {os.path.basename(final_path)}")
                             # Rename lyrics sidecar file to match the output filename