pdf

# PDF Read `${SKILL_DIR}/../_shared/artifacts.md` for setup and rendering. Use `pypdf` for metadata, extraction, page operations, and forms; use ReportLab for new PDFs. Inspect page count, dimensions, text availability, encryption, annotations, and form fields before modifying an existing document. Scanned pages need an available OCR engine; lack of extracted text is not an empty page. Keep exact page references for extracted claims and do not invent missing text. For a fillable form, inspect `PdfReader.get_fields()` and each widget's field type, export values, and flags. Map the user's answers to field identifiers; derive nothing sensitive or consequential merely to complete a form. Clone the document with `PdfWriter`, update fields using its documented API, and preserve interactive widgets unless flattening is requested. Check checkboxes using the actual export state. Signed or encrypted PDFs require a compatible authorized workflow; modifying a signed file may invalidate its signature. Save to a separate file, reopen it, inspect field values and annotations, and render the completed pages. Confirm glyphs, form appearances, pagination, and content placement. Fix overflow and missing appearances before delivery. Report when a native viewer's form behavior or signature verification was not tested.