Casefold before calculating indices

Complete case difference for a opinion/aspect term broke a row

src/alignment.py

@@ -122,6 +122,9 @@ def _is_sequential(span: tuple[int, ...]) -> bool:
 
 
 def _aligned_character_indices(original: str, replacement: str) -> list[Optional[int]]:
+    original = original.casefold()
+    replacement = replacement.casefold()
+
     indices: list[Optional[int]] = list(range(len(original)))
     for operation, _source_position, destination_position in Levenshtein.editops(
         original, replacement