refactor(application): update processor interfaces for Stream API

- IPdfProcessor: ValidateAsync, ValidatePdfAAsync, CheckAttachmentsAsync now accept Stream
- ISwissQrCodeProcessor: ExtractSwissQrCodeAsync now accepts Stream
- Update XML documentation: Position=0 requirement, non-seekable stream support
- Exception documentation: BadRequestException for validation errors (stream empty/invalid/wrong position)

DocumentOperator.Application/Common/Interfaces/IPdfProcessor.cs

@@ -7,30 +7,39 @@ public interface IPdfProcessor
     /// <summary>
     /// Validates a PDF and extracts metadata.
     /// </summary>
-    /// <param name="pdfStream">PDF content as stream (caller is responsible for disposal)</param>
+    /// <param name="pdfStream">
+    /// PDF document stream. Must be readable and positioned at the beginning (Position = 0).
+    /// Non-seekable streams are supported. Caller is responsible for disposal.
+    /// </param>
     /// <returns>PDF metadata (page count, size, version, attachments)</returns>
     /// <exception cref="Domain.Common.Exceptions.BadRequestException">
-    /// Thrown when stream is empty or invalid
+    /// Thrown when stream is empty, invalid, or not positioned at the beginning
     /// </exception>
     Task<PdfMetadata> ValidateAsync(Stream pdfStream);
 
     /// <summary>
     /// Validates a PDF/A document and checks conformance level.
     /// </summary>
-    /// <param name="pdfStream">PDF content as stream (caller is responsible for disposal)</param>
+    /// <param name="pdfStream">
+    /// PDF document stream. Must be readable and positioned at the beginning (Position = 0).
+    /// Non-seekable streams are supported. Caller is responsible for disposal.
+    /// </param>
     /// <returns>PDF/A metadata including conformance level and validation errors/warnings</returns>
     /// <exception cref="Domain.Common.Exceptions.BadRequestException">
-    /// Thrown when stream is empty or invalid
+    /// Thrown when stream is empty, invalid, or not positioned at the beginning
     /// </exception>
     Task<PdfAMetadata> ValidatePdfAAsync(Stream pdfStream);
 
     /// <summary>
     /// Checks for embedded files (attachments) in a PDF document and returns detailed metadata.
     /// </summary>
-    /// <param name="pdfStream">PDF content as stream (caller is responsible for disposal)</param>
+    /// <param name="pdfStream">
+    /// PDF document stream. Must be readable and positioned at the beginning (Position = 0).
+    /// Non-seekable streams are supported. Caller is responsible for disposal.
+    /// </param>
     /// <returns>Attachment information (count, file names, MIME types, sizes)</returns>
     /// <exception cref="Domain.Common.Exceptions.BadRequestException">
-    /// Thrown when stream is empty or invalid
+    /// Thrown when stream is empty, invalid, or not positioned at the beginning
     /// </exception>
     Task<AttachmentInfo> CheckAttachmentsAsync(Stream pdfStream);
 }