Refactor auth type to enum in RecActionDto and handler

Changed EndpointAuthType from string to enum in RecActionDto. Updated InvokeRecActionCommandHandler to use enum values in switch statements for improved type safety and maintainability.

src/ReC.Application/Common/Dto/RecActionDto.cs

@@ -21,7 +21,7 @@ public record RecActionDto
 
     public long? EndpointAuthId { get; init; }
 
-    public string? EndpointAuthType { get; init; }
+    public EndpointAuthType? EndpointAuthType { get; init; }
 
     public string? EndpointAuthApiKey { get; init; }