Rebrand project: DocumentOperator to DocumentService

This commit implements a complete rebranding of the project:
- Updated all namespaces from `DocumentOperator` to `DocumentService`.
- Renamed file paths, embedded resources, and test data references.
- Updated configuration keys, logging paths, and Redis instance names.
- Revised documentation to reflect the new project name.
- Modified project and solution files to align with the new structure.
- Updated class names, DTOs, commands, queries, and handlers.
- Adjusted middleware, controllers, and API endpoints.
- Updated Swagger metadata and API titles to `DocumentService API`.
- Refactored test namespaces, resource paths, and embedded resources.
- Updated build and deployment configurations for the new name.
- Replaced all references to `DocumentOperator` in comments and literals.

These changes ensure consistency across the codebase and documentation.

DocumentOperator.Tests/Integration/API/PdfOperationsControllerTests.cs

@@ -3,12 +3,12 @@ using System.Net.Http.Headers;
 using System.Reflection;
 using System.Text;
 using System.Text.Json;
-using DocumentOperator.API.Controllers;
-using DocumentOperator.Domain.Models.ValueObjects;
+using DocumentService.API.Controllers;
+using DocumentService.Domain.Models.ValueObjects;
 using FluentAssertions;
 using Microsoft.AspNetCore.Mvc.Testing;
 
-namespace DocumentOperator.Tests.Integration.API;
+namespace DocumentService.Tests.Integration.API;
 
 public class PdfOperationsControllerTests : IClassFixture<WebApplicationFactory<Program>>
 {
@@ -22,7 +22,7 @@ public class PdfOperationsControllerTests : IClassFixture<WebApplicationFactory<
     private static Stream LoadTestPdfAsStream(string fileName)
     {
         var assembly = Assembly.GetExecutingAssembly();
-        var resourceName = $"DocumentOperator.Tests.TestData.Pdfs.{fileName}";
+        var resourceName = $"DocumentService.Tests.TestData.Pdfs.{fileName}";
         return assembly.GetManifestResourceStream(resourceName) 
                ?? throw new FileNotFoundException($"Embedded resource not found: {resourceName}");
     }