Phase 6: Document Creation and Mutation

[tlkahn]

Goal

Create PDFs from scratch, add/remove pages and objects, save to file or bytes.

Tasks

• Add creation FFI: FPDF_CreateNewDocument, FPDFPage_New, FPDFPage_Delete, FPDFPageObj_CreateTextObj, FPDFPage_InsertObject, FPDFPage_RemoveObject, FPDFPage_GenerateContent, FPDF_SaveAsCopy
• Add font FFI: FPDFText_LoadFont, FPDFText_LoadStandardFont
• Implement Document::new(), Document::create_page(), Document::delete_page()
• Implement FontRef and Document::add_builtin_font(), Document::add_font_from_bytes()
• Implement object creation: create_text_object(), create_path_object(), create_image_object()
• Implement Document::remove_object(), Document::move_object_to_page()
• Implement content regeneration tracking (needs_content_regen flag on PageData)
• Implement Document::save(), Document::to_bytes(), Document::write_to()
• Tests: create PDF from scratch with text and images, save, re-open and verify content
• Write examples/create.rs

Exit Criterion

Can create a multi-page PDF with text and images from scratch, save it, and re-open it successfully.

Dependencies

• Phase 5: Page Objects #6 (Phase 5: Page Objects)