feat: add envelope delete command and API endpoint

EnvelopeGenerator.API/Controllers/EnvelopeController.cs

@@ -27,6 +27,8 @@ namespace EnvelopeGenerator.API.Controllers;
 [Authorize]
 public class EnvelopeController : ControllerBase
 {
+    public record DeleteEnvelopeRequest(string Reason);
+
     private readonly ILogger<EnvelopeController> _logger;
     private readonly IMediator _mediator;
 
@@ -108,4 +110,17 @@ public class EnvelopeController : ControllerBase
         else
             return Ok(res);
     }
-}
+
+    [Authorize(AuthenticationSchemes = AuthScheme.Sender)]
+    [HttpDelete("{id:int}")]
+    public async Task<IActionResult> DeleteAsync([FromRoute] int id, [FromBody] DeleteEnvelopeRequest request)
+    {
+        var result = await _mediator.Send(new DeleteEnvelopeCommand
+        {
+            EnvelopeId = id,
+            Reason = request?.Reason ?? string.Empty
+        }.WithAuth(User.GetId()));
+
+        return Ok(result);
+    }
+}

EnvelopeGenerator.API/Middleware/ExceptionHandlingMiddleware.cs

@@ -69,6 +69,11 @@ public class ExceptionHandlingMiddleware
                 message = notFoundEx.Message;
                 break;
 
+            case ForbiddenException forbiddenEx:
+                context.Response.StatusCode = (int)HttpStatusCode.Forbidden;
+                message = forbiddenEx.Message;
+                break;
+
             default:
                 logger.LogError(exception, "Unhandled exception occurred.");
                 context.Response.StatusCode = (int)HttpStatusCode.InternalServerError;