Refactored `PdfSignOptionsDto` and `PdfVisualSignatureOptionsDto`:
- Converted both to immutable `record` types with non-nullable properties.
- Added XML documentation comments for properties and parameters.
Simplified `PdfDigitalSignatureService`:
- Updated `SignPdfAsync` to enforce non-nullable `PdfSignOptionsDto`.
- Removed redundant null checks and inlined `CreateSignatureBounds`.
- Simplified signature appearance and image data logic.
- Refactored `TryGetKeySize` to use `bool` with `out` parameter.
General improvements:
- Enhanced code readability and maintainability.
- Reduced nullable references and enforced stricter type safety.
TekH
57a08e8a89