chore: Add Serilog.UI packages + versioning metadata

Packages:
- Serilog.Sinks.SQLite 7.0.0 (SQLite log persistence)
- Serilog.UI 3.2.0 (Web-based log viewer)
- Serilog.UI.SqliteProvider 1.1.0 (SQLite provider for Serilog.UI)

Versioning metadata:
- Version: 1.0.0
- Authors/Company: Digital Data GmbH
- Copyright: 2026
- Description: PDF document processing service using DevExpress

DocumentOperator.API/DocumentOperator.API.csproj

@@ -4,7 +4,18 @@
     <TargetFramework>net8.0</TargetFramework>
     <Nullable>enable</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>
-	<GenerateDocumentationFile>true</GenerateDocumentationFile>
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
+    <PackageId>DocumentOperator.API</PackageId>
+    <Authors>Digital Data GmbH</Authors>
+    <Company>Digital Data GmbH</Company>
+    <Product>DocumentOperator.API</Product>
+    <Version>1.0.0</Version>
+    <FileVersion>1.0.0.0</FileVersion>
+    <AssemblyVersion>1.0.0.0</AssemblyVersion>
+    <InformationalVersion>1.0.0</InformationalVersion>
+    <Copyright>Copyright © 2026 Digital Data GmbH. All rights reserved.</Copyright>
+    <Description>PDF Document Operations REST API - Validation, Swiss QR Code extraction, attachments, merge, annotation, stamp operations powered by DevExpress Office File API</Description>
+    <PackageTags>pdf document operator validation swiss-qr-code annotations stamp devexpress</PackageTags>
   </PropertyGroup>
 
   <ItemGroup>
@@ -13,6 +24,9 @@
     <PackageReference Include="Serilog.AspNetCore" Version="10.0.0" />
     <PackageReference Include="Serilog.Enrichers.Environment" Version="3.0.1" />
     <PackageReference Include="Serilog.Sinks.File" Version="7.0.0" />
+    <PackageReference Include="Serilog.Sinks.SQLite" Version="7.0.0" />
+    <PackageReference Include="Serilog.UI" Version="3.2.0" />
+    <PackageReference Include="Serilog.UI.SqliteProvider" Version="1.1.0" />
     <PackageReference Include="Swashbuckle.AspNetCore" Version="6.6.2" />
   </ItemGroup>