Print warning if album art isn't named correctly

src/transcode/transcoder.py

@@ -72,7 +72,14 @@ class Transcoder:
     def copy_album_art(in_dir: Path, out_dir: Path, file_whitelist: list = None):
         if file_whitelist is None:
             file_whitelist = ['.jpg', '.jpeg', '.png']
+        art_file_name = "cover.jpg"
 
+        art_found = False
         for file in in_dir.iterdir():
             if file.is_file() and file.suffix.lower() in file_whitelist:
+                if file.name == art_file_name:
+                    art_found = True
                 shutil.copy(file, out_dir / file.name)
+
+        if not art_found:
+            print(f"Warning: {art_file_name} not found in {in_dir}")