Function plan_pdf_fill_annotation 

pub fn plan_pdf_fill_annotation(
    bytes: &[u8],
    r: &PdfFillAnnotationRequest,
) -> Result<PdfFillAnnotationPlan, String>

Create opaque polygonal fill pages through canonical product authoring and geometry. An exact page converts as is; a page with visible unsupported content converts only when the request quotes its fidelity report digest, and the omissions are recorded with the annotation. Raster-only pages and geometric qualification failures refuse the whole page.