Add XML documentation for improved code clarity

Added detailed XML documentation across multiple files to enhance
code maintainability and readability. Key updates include:

- Documented `AllowAllDashboardAuthorizationFilter` to clarify
  its development-only usage.
- Added comments to `DtoExtensions` for Hangfire job ID generation
  and DTO-to-command conversion methods.
- Enhanced `HealthCheckHtmlGenerator` with detailed descriptions
  of HTML generation methods and utility functions.
- Documented `DependencyInjection` and `ProfileWorkerOptionsValidator`
  to explain service registration and configuration validation.
- Updated `ProfileCache` with comments on thread-safe operations.
- Added documentation to `ProfileWork` for profile synchronization
  logic and execution flow.
- Enhanced `ProfileWorker` with health check logic and background
  service execution details.
- Documented `ProfileWorkerOptions` configuration properties.

These changes aim to improve developer understanding and ensure
best practices are followed in production environments.

ECMJobRunner.WebCron/AllowAllDashboardAuthorizationFilter.cs

@@ -8,6 +8,11 @@ namespace ECMJobRunner.WebCron
     /// </summary>
     public class AllowAllDashboardAuthorizationFilter : IDashboardAuthorizationFilter
     {
+        /// <summary>
+        /// Determines whether the current user is authorized to access the Hangfire Dashboard.
+        /// </summary>
+        /// <param name="context">The Hangfire dashboard context containing request information.</param>
+        /// <returns>Always returns <c>true</c> to allow all users (development only).</returns>
         public bool Authorize(DashboardContext context)
         {
             // Allow all users - FOR DEVELOPMENT ONLY