feat(domain): add workflow API core models and meta codes

src/core/DigitalData.TaskFlow.Domain/Workflows/ClosingMethodItem.cs

@@ -0,0 +1,27 @@
+namespace DigitalData.TaskFlow.Domain.Workflows;
+
+/// <summary>
+/// Represents a workflow closing option available for user decision.
+/// </summary>
+public sealed record ClosingMethodItem
+{
+    /// <summary>
+    /// Gets the closing method identifier.
+    /// </summary>
+    public required int ClosingMethodId { get; init; }
+
+    /// <summary>
+    /// Gets the display name of the method.
+    /// </summary>
+    public required string Name { get; init; }
+
+    /// <summary>
+    /// Gets a value indicating whether a comment is mandatory for this method.
+    /// </summary>
+    public required bool CommentRequired { get; init; }
+
+    /// <summary>
+    /// Gets a value indicating whether this method represents a rejection.
+    /// </summary>
+    public required bool IsRejection { get; init; }
+}