Added enums `PdfSignatureCoordinateUnit` and `PdfSignatureCoordinateOrigin` to support defining signature coordinates in points or inches and relative to either the bottom-left or top-left corner of the page.
Updated `PdfSignatureAppearanceDto` to include `CoordinateUnit` and `CoordinateOrigin` parameters with default values. Refactored `PdfDigitalSignatureService` to use a new `BuildSignatureBounds` method for calculating signature bounds, which handles unit conversion, origin adjustments, and validation.
Introduced `GetPageHeightInPoints` to retrieve page height for top-left origin calculations. Improved signature field naming precision and added error handling for invalid dimensions and page numbers.
Included a TODO for optimizing the signature check algorithm.
Refactored `Pkcs11Options` by removing `DefaultCertificationLevel` and improving property documentation. Replaced `VisualSignature` in `PdfSignOptionsDto` with `Appearance` using the new `PdfSignatureAppearanceDto` class, which encapsulates signature appearance details, including font and color settings.
Enhanced `PdfSignatureCertificationLevel` enum with more descriptive values and added XML documentation. Updated `IPdfDigitalSignatureService` to support optional signature images and removed redundant methods.
Refactored `PdfDigitalSignatureService` to streamline appearance handling, validate inputs, and improve maintainability. Removed unused methods and added support for `PdfSignatureAppearanceDto`.
Simplified `PdfSignatureController` by consolidating form properties into `PdfSignOptionsDto`. Improved code readability and flexibility while removing redundant logic.
