Support recursive search of MP3 files in subfolders; update input prompt message

src/app.py

@@ -11,8 +11,8 @@ GROUP_SIZE = 5
 # Store the current date
 run_date = datetime.now().strftime("%Y-%m-%d_%H-%M-%S")
 
-# Ask for source path
-source_input = input("Enter the full path to your source MP3 folder: ").strip().strip('"')
+# Ask for source path, strip quotes if pasted
+source_input = input("Drag and drop your music folder here, then press Enter: ").strip().strip('"')
 source_media_path = Path(source_input)
 
 if not source_media_path.exists() or not source_media_path.is_dir():
@@ -35,9 +35,9 @@ def get_bpm(file_path):
         print(f"Skipping {file_path.name} (no BPM): {e}")
     return None
 
-# Collect all tracks, grouping unknown BPM separately
+# Collect all tracks recursively, grouping unknown BPM separately
 all_tracks = []
-for file in source_media_path.glob("*.mp3"):
+for file in source_media_path.rglob("*.mp3"):  # <-- recursive glob
     bpm = get_bpm(file)
     size = file.stat().st_size
     if bpm is None: