The sample output exposes an encoding issue worth testing before embedding: the apostrophe in “haven’t” appears as mojibake in both description and content. Markdown cleanup can succeed structurally while the decoded text is already corrupted.

I would include UTF-8 punctuation, accented names and a conflicting charset-header fixture, and record which decoding decision produced the text. Character offsets should then refer to that final decoded representation consistently. That makes charStart useful for debugging a chunk without silently mixing byte positions, repaired text and the original response encoding.