feat(application): map closing outcomes to API exceptions

src/core/DigitalData.TaskFlow.Application/Common/Exceptions/ApiException.cs

@@ -0,0 +1,32 @@
+using DigitalData.TaskFlow.Domain.Enums;
+
+namespace DigitalData.TaskFlow.Application.Common.Exceptions;
+
+/// <summary>
+/// Represents an API-facing exception that carries HTTP and domain meta information.
+/// </summary>
+public class ApiException : Exception
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ApiException"/> class.
+    /// </summary>
+    /// <param name="statusCode">HTTP status code to return.</param>
+    /// <param name="metaCode">Domain meta code to return.</param>
+    /// <param name="message">Response message.</param>
+    public ApiException(int statusCode, MetaCode metaCode, string message)
+        : base(message)
+    {
+        StatusCode = statusCode;
+        MetaCode = metaCode;
+    }
+
+    /// <summary>
+    /// Gets the HTTP status code.
+    /// </summary>
+    public int StatusCode { get; }
+
+    /// <summary>
+    /// Gets the domain meta code.
+    /// </summary>
+    public MetaCode MetaCode { get; }
+}

src/core/DigitalData.TaskFlow.Application/Common/Exceptions/ConflictApiException.cs

@@ -0,0 +1,19 @@
+using DigitalData.TaskFlow.Domain.Enums;
+
+namespace DigitalData.TaskFlow.Application.Common.Exceptions;
+
+/// <summary>
+/// Represents a 409 API exception.
+/// </summary>
+public sealed class ConflictApiException : ApiException
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ConflictApiException"/> class.
+    /// </summary>
+    /// <param name="metaCode">Domain meta code to return.</param>
+    /// <param name="message">Response message.</param>
+    public ConflictApiException(MetaCode metaCode, string message)
+        : base(409, metaCode, message)
+    {
+    }
+}

src/core/DigitalData.TaskFlow.Application/Common/Exceptions/NotFoundApiException.cs

@@ -0,0 +1,18 @@
+using DigitalData.TaskFlow.Domain.Enums;
+
+namespace DigitalData.TaskFlow.Application.Common.Exceptions;
+
+/// <summary>
+/// Represents a 404 API exception.
+/// </summary>
+public sealed class NotFoundApiException : ApiException
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="NotFoundApiException"/> class.
+    /// </summary>
+    /// <param name="message">Response message.</param>
+    public NotFoundApiException(string message)
+        : base(404, MetaCode.NotFound, message)
+    {
+    }
+}