feat: add EstimatedMinutes field and general PUT update endpoint for tasks

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

TaskTracker.Core/DTOs/CreateTaskRequest.cs

@@ -6,4 +6,5 @@ public class CreateTaskRequest
     public string? Description { get; set; }
     public string? Category { get; set; }
     public int? ParentTaskId { get; set; }
+    public int? EstimatedMinutes { get; set; }
 }

TaskTracker.Core/DTOs/UpdateTaskRequest.cs

@@ -0,0 +1,9 @@
+namespace TaskTracker.Core.DTOs;
+
+public class UpdateTaskRequest
+{
+    public string? Title { get; set; }
+    public string? Description { get; set; }
+    public string? Category { get; set; }
+    public int? EstimatedMinutes { get; set; }
+}

TaskTracker.Core/Entities/WorkTask.cs

@@ -12,6 +12,7 @@ public class WorkTask
     public DateTime CreatedAt { get; set; }
     public DateTime? StartedAt { get; set; }
     public DateTime? CompletedAt { get; set; }
+    public int? EstimatedMinutes { get; set; }
 
     public int? ParentTaskId { get; set; }
     public WorkTask? ParentTask { get; set; }