Refactor PDF handling and update config

Simplified the return logic in `SwissQrCodeController` by removing conditional checks and directly returning the result.

Refactored `DevExpressPdfProcessor` to handle encrypted PDFs more effectively by checking for encryption before attempting to load with DevExpress, thus avoiding potential errors. Metadata extraction is now limited to non-encrypted PDFs.

Added `opencode.jsonc` configuration file to define schema and specify paths for integrating external AI skills with the OpenCode AI platform.

DocumentService.API/Controllers/SwissQrCodeController.cs

@@ -55,7 +55,7 @@ public class SwissQrCodeController(IMediator Mediator) : ControllerBase
         };
         var result = await Mediator.Send(query, cancellationToken);
 
-        return Ok(raw ? result.RawLines : result.Bill);
+        return Ok(result);
     }
 
     /// <summary>
@@ -97,7 +97,7 @@ public class SwissQrCodeController(IMediator Mediator) : ControllerBase
         var query = new ExtractSwissQrCodeQuery { PdfStream = pdfStream };
         var result = await Mediator.Send(query, cancellationToken);
 
-        return Ok(raw ? result.RawLines : result.Bill);
+        return Ok(result);
     }
 }