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.API/Configuration/DualInputDocumentFilter.cs

@@ -2,7 +2,7 @@ using Microsoft.AspNetCore.Mvc.ApiExplorer;
 using Microsoft.OpenApi.Models;
 using Swashbuckle.AspNetCore.SwaggerGen;
 
-namespace DocumentOperator.API.Configuration
+namespace DocumentService.API.Configuration
 {
     /// <summary>
     /// Swagger document filter that merges operations with same path but different [Consumes] attributes.

DocumentOperator.API/Configuration/SerilogConfiguration.cs

@@ -1,4 +1,4 @@
-namespace DocumentOperator.API.Configuration
+namespace DocumentService.API.Configuration
 {
     /// <summary>
     /// Placeholder class for Serilog configuration extensions.

DocumentOperator.API/Configuration/SwaggerConfiguration.cs

@@ -2,7 +2,7 @@
 using Microsoft.OpenApi.Models;
 using System.Reflection;
 
-namespace DocumentOperator.API.Configuration
+namespace DocumentService.API.Configuration
 {
     /// <summary>
     /// Provides extension methods for configuring Swagger/OpenAPI documentation.

DocumentOperator.API/Configuration/SwaggerSettings.cs

@@ -1,4 +1,4 @@
-namespace DocumentOperator.API.Configuration;
+namespace DocumentService.API.Configuration;
 
 /// <summary>
 /// Configuration settings for Swagger/OpenAPI documentation.
@@ -19,7 +19,7 @@ public class SwaggerSettings
     /// <summary>
     /// API title displayed in Swagger UI.
     /// </summary>
-    public string Title { get; set; } = "DocumentOperator API";
+    public string Title { get; set; } = "DocumentService API";
 
     /// <summary>
     /// API version.