REST Chunking

curl -X POST http://127.0.0.1:8000/v1/chunk \
  -H "Content-Type: application/json" \
  -d '{
    "markdown": [
      { "id": "doc-1", "text": "# Guide\n\nRagrails builds modular RAG workflows...", "source": "files/guide.pdf", "metadata": {"title": "Guide"} }
    ],
    "chunk_size": 2000,
    "chunk_overlap": 200,
    "min_chunk_length": 100
  }'

{
  "inputs": 1,
  "chunks": 3,
  "items": [
    { "id": "doc-1-0", "text": "Ragrails builds modular RAG workflows...", "source": "files/guide.pdf", "metadata": {"title": "Guide", "chunk_index": 0} }
  ],
  "failed": 0,
  "errors": []
}