v1.5.0

Added

• PDF/A production. PdfSaveOptions.PdfA (PdfAOptions: part 2 or 3, level B or U) writes ISO 19005-2/-3 files from a full save: it first adds an sRGB output intent (a version 2 ICC profile OnePDF generates from the published sRGB parameters) and an XMP packet built from the Info dictionary, sets the Print flag and stores generated appearances on annotations, clears /NeedAppearances once every widget has an appearance, and embeds Liberation faces (from RecursiveAI.OnePdf.Fonts) for standard fonts OnePDF itself added. What is still wrong is refused with PdfAException, whose Violations list every problem with its clause, object and page: non-embedded fonts, CMYK, encryption, JavaScript and other forbidden actions, LZW, embedded files in part 2, missing appearances, level U fonts without Unicode mapping and more. PdfDocument.CheckPdfA reports without changing anything, PreparePdfA makes the repairs, and PdfDocument.AttachFile adds attachments for part 3. Output is deterministic with PdfSaveOptions.DocumentId. A pdfa fuzz target covers it. See docs/pdfa.md.
• XmpMetadata.PdfAPart and PdfAConformance read the PDF/A identification of a packet.

Fixed

• Importing pages from a document whose fonts were added with AddFont copied the font before its subset had been built; the imported text drew with an empty font program. The source's fonts are now finished before pages are copied.