Add handling for files without BPM: group into [Unknown BPM] folder; keep balanced CD splits and timestamped output folder

src/app.py

@@ -35,16 +35,21 @@ def get_bpm(file_path):
         print(f"Skipping {file_path.name} (no BPM): {e}")
     return None
 
-# Collect all tracks
+# Collect all tracks, grouping unknown BPM separately
 all_tracks = []
 for file in source_media_path.glob("*.mp3"):
     bpm = get_bpm(file)
-    if bpm is None:
-        continue
     size = file.stat().st_size
-    bpm_range = f"{(bpm // GROUP_SIZE) * GROUP_SIZE}-to-{((bpm // GROUP_SIZE) * GROUP_SIZE) + GROUP_SIZE - 1}"
+    if bpm is None:
+        bpm_range = "[Unknown BPM]"
+    else:
+        bpm_range = f"{(bpm // GROUP_SIZE) * GROUP_SIZE}-to-{((bpm // GROUP_SIZE) * GROUP_SIZE) + GROUP_SIZE - 1}"
     all_tracks.append({"file": file, "size": size, "bpm_range": bpm_range})
 
+if not all_tracks:
+    print("No MP3 files found.")
+    exit(0)
+
 # Calculate total size and number of CDs needed
 total_size = sum(t["size"] for t in all_tracks)
 num_cds = max(1, (total_size + CD_SIZE - 1) // CD_SIZE)
@@ -89,3 +94,5 @@ for i, tracks in enumerate(cd_contents, start=1):
         size_accum += track["size"]
     print(f"[WRITE] CD-{i:02}: {len(tracks)} tracks, approx {size_accum/1024**2:.2f} MB")
 
+print("\n✅ Done!")
+