Fix output to preserve internal tuple order

- Remove sorted_by_frequency from write functions
- Output now uses internal chord._pitches order instead of sorted

compact_sets.py

@@ -843,7 +843,7 @@ def write_chord_sequence(seq: list[Chord], path: str) -> None:
     serializable = []
     for chord in seq:
         chord_data = []
-        for pitch in chord.sorted_by_frequency():
+        for pitch in chord._pitches:
             chord_data.append(
                 {
                     "hs_array": list(pitch.hs_array),
@@ -868,7 +868,7 @@ def write_chord_sequence_readable(seq: list[Chord], path: str) -> None:
     with open(path, "w") as f:
         f.write("(\n")
         for i, chord in enumerate(seq):
-            arrays = tuple(p.hs_array for p in chord.sorted_by_frequency())
+            arrays = tuple(p.hs_array for p in chord._pitches)
             f.write(f"  {arrays},\n")
         f.write(")\n")