RAG chunking simulator

This is a dry run, not an index: nothing is embedded, stored, or sent anywhere, and the token number is the characters divided by 4 heuristic, not a tokenizer count. The sentence scanner treats every period, question mark and exclamation mark as an end, so abbreviations like e.g. split like sentence ends. Overlap carries whole sentences, paragraphs or words (raw characters for the fixed strategy), and a chunk whose single piece is longer than the ceiling is kept whole and flagged rather than cut mid-content. Check the size spread and boundary view here, then commit to the embedding run.