Refactored `DevExpressPdfProcessor` to improve attachment detection:
- Changed `DetectEmbeddedFiles` return type to a tuple for better
handling of attachment presence and count.
- Enhanced logic to parse `/Names` arrays and count object references
for accurate attachment detection.
- Implemented robust search for `/EmbeddedFiles` to handle multiple
occurrences and ensure proper context validation.
Updated PHASENPLAN.md and ROADMAP.md to reflect these changes, including
the addition of fixes for attachment detection and counting logic.
Added new tests in `DevExpressPdfProcessorTests`:
- Verified detection of multiple attachments and accurate counts.
- Ensured no crashes when processing PDFs with `/EmbeddedFiles`.
Included a new test resource (`pdfWithMoreThanOneAttachment.pdf`) for
validating multiple attachment scenarios.
Updated PHASENPLAN.md and ROADMAP.md to reflect a complete restructuring of the development plan and added a "Bugfix: Attachment Detection" entry.
Implemented attachment detection in DevExpressPdfProcessor.cs using the new `DetectEmbeddedFiles` method, which scans raw PDF data for the `/EmbeddedFiles` keyword. Updated the `hasAttachments` property to use this method and set `attachmentCount` to `-1` when attachments are detected.
Added a new test, `ValidateAsync_PdfWithoutAttachments_ReturnsNoAttachments`, in DevExpressPdfProcessorTests.cs to verify that PDFs without attachments are correctly identified. Included a note about future testing for PDFs with attachments using ZUGFeRD files.
All related tests are passing (12/12 green).
Eliminated a redundant `using DevExpress.Pdf;` statement to improve code readability and maintain cleaner imports. This change has no functional impact but enhances code clarity.
Replaced `DevExpress.Pdf.Core` with `DevExpress.Document.Processor` in `DocumentOperator.Infrastructure.csproj` to adopt a newer library for PDF processing. Removed the `Services\PdfProcessing\` folder reference.
Updated `DevExpressPdfProcessorTests` to reflect changes in the `ValidateAsync` method's behavior.
Introduced the `DevExpressPdfProcessor` class, implementing the `IPdfProcessor` interface. This class validates PDF documents and extracts metadata using the `DevExpress.Pdf` library. Added defensive input validation, metadata extraction, and exception handling for domain consistency.
