refactor: implement unified startup validator architecture with IStartupValidator interface

octo-fiesta/Services/Validation/IStartupValidator.cs

@@ -0,0 +1,19 @@
+namespace octo_fiesta.Services.Validation;
+
+/// <summary>
+/// Interface for service startup validators
+/// </summary>
+public interface IStartupValidator
+{
+    /// <summary>
+    /// Gets the name of the service being validated
+    /// </summary>
+    string ServiceName { get; }
+
+    /// <summary>
+    /// Validates the service configuration and connectivity
+    /// </summary>
+    /// <param name="cancellationToken">Cancellation token</param>
+    /// <returns>Validation result containing status and details</returns>
+    Task<ValidationResult> ValidateAsync(CancellationToken cancellationToken);
+}