When markitdown is installed but a format-specific sub-dependency is
missing (e.g. pdfminer-six for PDF), translate the raw traceback into
a DependencyMissingError with the correct install command.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Uses markitdown-no-magika (lighter fork without magika/onnxruntime) to
handle PDF, HTML, DOCX, PPTX, XLSX, XLS, CSV, JSON, and XML files.
Specialized extractors (pymupdf4llm, markdownify) remain as fallbacks
when markitdown is not installed.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
