Project Init

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

colaflow-api/src/ColaFlow.Domain/Aggregates/ProjectAggregate/Epic.cs

@@ -0,0 +1,90 @@
+using ColaFlow.Domain.Common;
+using ColaFlow.Domain.Exceptions;
+using ColaFlow.Domain.ValueObjects;
+
+namespace ColaFlow.Domain.Aggregates.ProjectAggregate;
+
+/// <summary>
+/// Epic Entity (part of Project aggregate)
+/// </summary>
+public class Epic : Entity
+{
+    public new EpicId Id { get; private set; }
+    public string Name { get; private set; }
+    public string Description { get; private set; }
+    public ProjectId ProjectId { get; private set; }
+    public WorkItemStatus Status { get; private set; }
+    public TaskPriority Priority { get; private set; }
+
+    private readonly List<Story> _stories = new();
+    public IReadOnlyCollection<Story> Stories => _stories.AsReadOnly();
+
+    public DateTime CreatedAt { get; private set; }
+    public UserId CreatedBy { get; private set; }
+    public DateTime? UpdatedAt { get; private set; }
+
+    // EF Core constructor
+    private Epic()
+    {
+        Id = null!;
+        Name = null!;
+        Description = null!;
+        ProjectId = null!;
+        Status = null!;
+        Priority = null!;
+        CreatedBy = null!;
+    }
+
+    public static Epic Create(string name, string description, ProjectId projectId, UserId createdBy)
+    {
+        if (string.IsNullOrWhiteSpace(name))
+            throw new DomainException("Epic name cannot be empty");
+
+        if (name.Length > 200)
+            throw new DomainException("Epic name cannot exceed 200 characters");
+
+        return new Epic
+        {
+            Id = EpicId.Create(),
+            Name = name,
+            Description = description ?? string.Empty,
+            ProjectId = projectId,
+            Status = WorkItemStatus.ToDo,
+            Priority = TaskPriority.Medium,
+            CreatedAt = DateTime.UtcNow,
+            CreatedBy = createdBy
+        };
+    }
+
+    public Story CreateStory(string title, string description, TaskPriority priority, UserId createdBy)
+    {
+        var story = Story.Create(title, description, this.Id, priority, createdBy);
+        _stories.Add(story);
+        return story;
+    }
+
+    public void UpdateDetails(string name, string description)
+    {
+        if (string.IsNullOrWhiteSpace(name))
+            throw new DomainException("Epic name cannot be empty");
+
+        if (name.Length > 200)
+            throw new DomainException("Epic name cannot exceed 200 characters");
+
+        Name = name;
+        Description = description ?? string.Empty;
+        UpdatedAt = DateTime.UtcNow;
+    }
+
+    public void UpdateStatus(WorkItemStatus newStatus)
+    {
+        Status = newStatus;
+        UpdatedAt = DateTime.UtcNow;
+    }
+
+    public void UpdatePriority(TaskPriority newPriority)
+    {
+        Priority = newPriority;
+        UpdatedAt = DateTime.UtcNow;
+    }
+}

colaflow-api/src/ColaFlow.Domain/Aggregates/ProjectAggregate/Project.cs

@@ -0,0 +1,113 @@
+using ColaFlow.Domain.Common;
+using ColaFlow.Domain.Events;
+using ColaFlow.Domain.Exceptions;
+using ColaFlow.Domain.ValueObjects;
+
+namespace ColaFlow.Domain.Aggregates.ProjectAggregate;
+
+/// <summary>
+/// Project Aggregate Root
+/// Enforces consistency boundary for Project -> Epic -> Story -> Task hierarchy
+/// </summary>
+public class Project : AggregateRoot
+{
+    public new ProjectId Id { get; private set; }
+    public string Name { get; private set; }
+    public string Description { get; private set; }
+    public ProjectKey Key { get; private set; }
+    public ProjectStatus Status { get; private set; }
+    public UserId OwnerId { get; private set; }
+
+    private readonly List<Epic> _epics = new();
+    public IReadOnlyCollection<Epic> Epics => _epics.AsReadOnly();
+
+    public DateTime CreatedAt { get; private set; }
+    public DateTime? UpdatedAt { get; private set; }
+
+    // EF Core constructor
+    private Project()
+    {
+        Id = null!;
+        Name = null!;
+        Description = null!;
+        Key = null!;
+        Status = null!;
+        OwnerId = null!;
+    }
+
+    // Factory method
+    public static Project Create(string name, string description, string key, UserId ownerId)
+    {
+        // Validation
+        if (string.IsNullOrWhiteSpace(name))
+            throw new DomainException("Project name cannot be empty");
+
+        if (name.Length > 200)
+            throw new DomainException("Project name cannot exceed 200 characters");
+
+        var project = new Project
+        {
+            Id = ProjectId.Create(),
+            Name = name,
+            Description = description ?? string.Empty,
+            Key = ProjectKey.Create(key),
+            Status = ProjectStatus.Active,
+            OwnerId = ownerId,
+            CreatedAt = DateTime.UtcNow
+        };
+
+        // Raise domain event
+        project.AddDomainEvent(new ProjectCreatedEvent(project.Id, project.Name, ownerId));
+
+        return project;
+    }
+
+    // Business methods
+    public void UpdateDetails(string name, string description)
+    {
+        if (string.IsNullOrWhiteSpace(name))
+            throw new DomainException("Project name cannot be empty");
+
+        if (name.Length > 200)
+            throw new DomainException("Project name cannot exceed 200 characters");
+
+        Name = name;
+        Description = description ?? string.Empty;
+        UpdatedAt = DateTime.UtcNow;
+
+        AddDomainEvent(new ProjectUpdatedEvent(Id, Name, Description));
+    }
+
+    public Epic CreateEpic(string name, string description, UserId createdBy)
+    {
+        if (Status == ProjectStatus.Archived)
+            throw new DomainException("Cannot create epic in an archived project");
+
+        var epic = Epic.Create(name, description, this.Id, createdBy);
+        _epics.Add(epic);
+
+        AddDomainEvent(new EpicCreatedEvent(epic.Id, epic.Name, this.Id));
+
+        return epic;
+    }
+
+    public void Archive()
+    {
+        if (Status == ProjectStatus.Archived)
+            throw new DomainException("Project is already archived");
+
+        Status = ProjectStatus.Archived;
+        UpdatedAt = DateTime.UtcNow;
+
+        AddDomainEvent(new ProjectArchivedEvent(Id));
+    }
+
+    public void Activate()
+    {
+        if (Status == ProjectStatus.Active)
+            throw new DomainException("Project is already active");
+
+        Status = ProjectStatus.Active;
+        UpdatedAt = DateTime.UtcNow;
+    }
+}

colaflow-api/src/ColaFlow.Domain/Aggregates/ProjectAggregate/Story.cs

@@ -0,0 +1,111 @@
+using ColaFlow.Domain.Common;
+using ColaFlow.Domain.Exceptions;
+using ColaFlow.Domain.ValueObjects;
+
+namespace ColaFlow.Domain.Aggregates.ProjectAggregate;
+
+/// <summary>
+/// Story Entity (part of Project aggregate)
+/// </summary>
+public class Story : Entity
+{
+    public new StoryId Id { get; private set; }
+    public string Title { get; private set; }
+    public string Description { get; private set; }
+    public EpicId EpicId { get; private set; }
+    public WorkItemStatus Status { get; private set; }
+    public TaskPriority Priority { get; private set; }
+    public decimal? EstimatedHours { get; private set; }
+    public decimal? ActualHours { get; private set; }
+    public UserId? AssigneeId { get; private set; }
+
+    private readonly List<WorkTask> _tasks = new();
+    public IReadOnlyCollection<WorkTask> Tasks => _tasks.AsReadOnly();
+
+    public DateTime CreatedAt { get; private set; }
+    public UserId CreatedBy { get; private set; }
+    public DateTime? UpdatedAt { get; private set; }
+
+    // EF Core constructor
+    private Story()
+    {
+        Id = null!;
+        Title = null!;
+        Description = null!;
+        EpicId = null!;
+        Status = null!;
+        Priority = null!;
+        CreatedBy = null!;
+    }
+
+    public static Story Create(string title, string description, EpicId epicId, TaskPriority priority, UserId createdBy)
+    {
+        if (string.IsNullOrWhiteSpace(title))
+            throw new DomainException("Story title cannot be empty");
+
+        if (title.Length > 200)
+            throw new DomainException("Story title cannot exceed 200 characters");
+
+        return new Story
+        {
+            Id = StoryId.Create(),
+            Title = title,
+            Description = description ?? string.Empty,
+            EpicId = epicId,
+            Status = WorkItemStatus.ToDo,
+            Priority = priority,
+            CreatedAt = DateTime.UtcNow,
+            CreatedBy = createdBy
+        };
+    }
+
+    public WorkTask CreateTask(string title, string description, TaskPriority priority, UserId createdBy)
+    {
+        var task = WorkTask.Create(title, description, this.Id, priority, createdBy);
+        _tasks.Add(task);
+        return task;
+    }
+
+    public void UpdateDetails(string title, string description)
+    {
+        if (string.IsNullOrWhiteSpace(title))
+            throw new DomainException("Story title cannot be empty");
+
+        if (title.Length > 200)
+            throw new DomainException("Story title cannot exceed 200 characters");
+
+        Title = title;
+        Description = description ?? string.Empty;
+        UpdatedAt = DateTime.UtcNow;
+    }
+
+    public void UpdateStatus(WorkItemStatus newStatus)
+    {
+        Status = newStatus;
+        UpdatedAt = DateTime.UtcNow;
+    }
+
+    public void AssignTo(UserId assigneeId)
+    {
+        AssigneeId = assigneeId;
+        UpdatedAt = DateTime.UtcNow;
+    }
+
+    public void UpdateEstimate(decimal hours)
+    {
+        if (hours < 0)
+            throw new DomainException("Estimated hours cannot be negative");
+
+        EstimatedHours = hours;
+        UpdatedAt = DateTime.UtcNow;
+    }
+
+    public void LogActualHours(decimal hours)
+    {
+        if (hours < 0)
+            throw new DomainException("Actual hours cannot be negative");
+
+        ActualHours = hours;
+        UpdatedAt = DateTime.UtcNow;
+    }
+}

colaflow-api/src/ColaFlow.Domain/Aggregates/ProjectAggregate/WorkTask.cs

@@ -0,0 +1,108 @@
+using ColaFlow.Domain.Common;
+using ColaFlow.Domain.Exceptions;
+using ColaFlow.Domain.ValueObjects;
+
+namespace ColaFlow.Domain.Aggregates.ProjectAggregate;
+
+/// <summary>
+/// Task Entity (part of Project aggregate)
+/// Named "WorkTask" to avoid conflict with System.Threading.Tasks.Task
+/// </summary>
+public class WorkTask : Entity
+{
+    public new TaskId Id { get; private set; }
+    public string Title { get; private set; }
+    public string Description { get; private set; }
+    public StoryId StoryId { get; private set; }
+    public WorkItemStatus Status { get; private set; }
+    public TaskPriority Priority { get; private set; }
+    public decimal? EstimatedHours { get; private set; }
+    public decimal? ActualHours { get; private set; }
+    public UserId? AssigneeId { get; private set; }
+
+    public DateTime CreatedAt { get; private set; }
+    public UserId CreatedBy { get; private set; }
+    public DateTime? UpdatedAt { get; private set; }
+
+    // EF Core constructor
+    private WorkTask()
+    {
+        Id = null!;
+        Title = null!;
+        Description = null!;
+        StoryId = null!;
+        Status = null!;
+        Priority = null!;
+        CreatedBy = null!;
+    }
+
+    public static WorkTask Create(string title, string description, StoryId storyId, TaskPriority priority, UserId createdBy)
+    {
+        if (string.IsNullOrWhiteSpace(title))
+            throw new DomainException("Task title cannot be empty");
+
+        if (title.Length > 200)
+            throw new DomainException("Task title cannot exceed 200 characters");
+
+        return new WorkTask
+        {
+            Id = TaskId.Create(),
+            Title = title,
+            Description = description ?? string.Empty,
+            StoryId = storyId,
+            Status = WorkItemStatus.ToDo,
+            Priority = priority,
+            CreatedAt = DateTime.UtcNow,
+            CreatedBy = createdBy
+        };
+    }
+
+    public void UpdateDetails(string title, string description)
+    {
+        if (string.IsNullOrWhiteSpace(title))
+            throw new DomainException("Task title cannot be empty");
+
+        if (title.Length > 200)
+            throw new DomainException("Task title cannot exceed 200 characters");
+
+        Title = title;
+        Description = description ?? string.Empty;
+        UpdatedAt = DateTime.UtcNow;
+    }
+
+    public void UpdateStatus(WorkItemStatus newStatus)
+    {
+        Status = newStatus;
+        UpdatedAt = DateTime.UtcNow;
+    }
+
+    public void AssignTo(UserId assigneeId)
+    {
+        AssigneeId = assigneeId;
+        UpdatedAt = DateTime.UtcNow;
+    }
+
+    public void UpdatePriority(TaskPriority newPriority)
+    {
+        Priority = newPriority;
+        UpdatedAt = DateTime.UtcNow;
+    }
+
+    public void UpdateEstimate(decimal hours)
+    {
+        if (hours < 0)
+            throw new DomainException("Estimated hours cannot be negative");
+
+        EstimatedHours = hours;
+        UpdatedAt = DateTime.UtcNow;
+    }
+
+    public void LogActualHours(decimal hours)
+    {
+        if (hours < 0)
+            throw new DomainException("Actual hours cannot be negative");
+
+        ActualHours = hours;
+        UpdatedAt = DateTime.UtcNow;
+    }
+}

colaflow-api/src/ColaFlow.Domain/ColaFlow.Domain.csproj

@@ -0,0 +1,9 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net9.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

colaflow-api/src/ColaFlow.Domain/Common/AggregateRoot.cs

@@ -0,0 +1,31 @@
+using ColaFlow.Domain.Events;
+
+namespace ColaFlow.Domain.Common;
+
+/// <summary>
+/// Base class for all aggregate roots
+/// </summary>
+public abstract class AggregateRoot : Entity
+{
+    private readonly List<DomainEvent> _domainEvents = new();
+
+    public IReadOnlyCollection<DomainEvent> DomainEvents => _domainEvents.AsReadOnly();
+
+    protected AggregateRoot() : base()
+    {
+    }
+
+    protected AggregateRoot(Guid id) : base(id)
+    {
+    }
+
+    protected void AddDomainEvent(DomainEvent domainEvent)
+    {
+        _domainEvents.Add(domainEvent);
+    }
+
+    public void ClearDomainEvents()
+    {
+        _domainEvents.Clear();
+    }
+}

colaflow-api/src/ColaFlow.Domain/Common/Entity.cs

@@ -0,0 +1,54 @@
+namespace ColaFlow.Domain.Common;
+
+/// <summary>
+/// Base class for all entities
+/// </summary>
+public abstract class Entity
+{
+    public Guid Id { get; protected set; }
+
+    protected Entity()
+    {
+        Id = Guid.NewGuid();
+    }
+
+    protected Entity(Guid id)
+    {
+        Id = id;
+    }
+
+    public override bool Equals(object? obj)
+    {
+        if (obj is not Entity other)
+            return false;
+
+        if (ReferenceEquals(this, other))
+            return true;
+
+        if (GetType() != other.GetType())
+            return false;
+
+        return Id == other.Id;
+    }
+
+    public static bool operator ==(Entity? a, Entity? b)
+    {
+        if (a is null && b is null)
+            return true;
+
+        if (a is null || b is null)
+            return false;
+
+        return a.Equals(b);
+    }
+
+    public static bool operator !=(Entity? a, Entity? b)
+    {
+        return !(a == b);
+    }
+
+    public override int GetHashCode()
+    {
+        return Id.GetHashCode();
+    }
+}

colaflow-api/src/ColaFlow.Domain/Common/Enumeration.cs

@@ -0,0 +1,78 @@
+using System.Reflection;
+
+namespace ColaFlow.Domain.Common;
+
+/// <summary>
+/// Base class for creating type-safe enumerations
+/// </summary>
+public abstract class Enumeration : IComparable
+{
+    public int Id { get; private set; }
+    public string Name { get; private set; }
+
+    protected Enumeration(int id, string name)
+    {
+        Id = id;
+        Name = name;
+    }
+
+    public override string ToString() => Name;
+
+    public static IEnumerable<T> GetAll<T>() where T : Enumeration
+    {
+        var fields = typeof(T).GetFields(BindingFlags.Public |
+                                          BindingFlags.Static |
+                                          BindingFlags.DeclaredOnly);
+
+        return fields.Select(f => f.GetValue(null)).Cast<T>();
+    }
+
+    public override bool Equals(object? obj)
+    {
+        if (obj is not Enumeration otherValue)
+        {
+            return false;
+        }
+
+        var typeMatches = GetType().Equals(obj.GetType());
+        var valueMatches = Id.Equals(otherValue.Id);
+
+        return typeMatches && valueMatches;
+    }
+
+    public override int GetHashCode() => Id.GetHashCode();
+
+    public static int AbsoluteDifference(Enumeration firstValue, Enumeration secondValue)
+    {
+        var absoluteDifference = Math.Abs(firstValue.Id - secondValue.Id);
+        return absoluteDifference;
+    }
+
+    public static T FromValue<T>(int value) where T : Enumeration
+    {
+        var matchingItem = Parse<T, int>(value, "value", item => item.Id == value);
+        return matchingItem;
+    }
+
+    public static T FromDisplayName<T>(string displayName) where T : Enumeration
+    {
+        var matchingItem = Parse<T, string>(displayName, "display name", item => item.Name == displayName);
+        return matchingItem;
+    }
+
+    private static T Parse<T, K>(K value, string description, Func<T, bool> predicate) where T : Enumeration
+    {
+        var matchingItem = GetAll<T>().FirstOrDefault(predicate);
+
+        if (matchingItem == null)
+            throw new InvalidOperationException($"'{value}' is not a valid {description} in {typeof(T)}");
+
+        return matchingItem;
+    }
+
+    public int CompareTo(object? other)
+    {
+        if (other == null) return 1;
+        return Id.CompareTo(((Enumeration)other).Id);
+    }
+}

colaflow-api/src/ColaFlow.Domain/Common/ValueObject.cs

@@ -0,0 +1,46 @@
+namespace ColaFlow.Domain.Common;
+
+/// <summary>
+/// Base class for all value objects
+/// </summary>
+public abstract class ValueObject
+{
+    protected abstract IEnumerable<object> GetAtomicValues();
+
+    public override bool Equals(object? obj)
+    {
+        if (obj == null || obj.GetType() != GetType())
+            return false;
+
+        var other = (ValueObject)obj;
+        return GetAtomicValues().SequenceEqual(other.GetAtomicValues());
+    }
+
+    public override int GetHashCode()
+    {
+        return GetAtomicValues()
+            .Aggregate(1, (current, obj) =>
+            {
+                unchecked
+                {
+                    return (current * 23) + (obj?.GetHashCode() ?? 0);
+                }
+            });
+    }
+
+    public static bool operator ==(ValueObject? a, ValueObject? b)
+    {
+        if (a is null && b is null)
+            return true;
+
+        if (a is null || b is null)
+            return false;
+
+        return a.Equals(b);
+    }
+
+    public static bool operator !=(ValueObject? a, ValueObject? b)
+    {
+        return !(a == b);
+    }
+}

colaflow-api/src/ColaFlow.Domain/Events/DomainEvent.cs

@@ -0,0 +1,10 @@
+namespace ColaFlow.Domain.Events;
+
+/// <summary>
+/// Base class for all domain events
+/// </summary>
+public abstract record DomainEvent
+{
+    public Guid EventId { get; init; } = Guid.NewGuid();
+    public DateTime OccurredOn { get; init; } = DateTime.UtcNow;
+}

colaflow-api/src/ColaFlow.Domain/Events/EpicCreatedEvent.cs

@@ -0,0 +1,12 @@
+using ColaFlow.Domain.ValueObjects;
+
+namespace ColaFlow.Domain.Events;
+
+/// <summary>
+/// Event raised when an epic is created
+/// </summary>
+public sealed record EpicCreatedEvent(
+    EpicId EpicId,
+    string EpicName,
+    ProjectId ProjectId
+) : DomainEvent;

colaflow-api/src/ColaFlow.Domain/Events/ProjectArchivedEvent.cs

@@ -0,0 +1,10 @@
+using ColaFlow.Domain.ValueObjects;
+
+namespace ColaFlow.Domain.Events;
+
+/// <summary>
+/// Event raised when a project is archived
+/// </summary>
+public sealed record ProjectArchivedEvent(
+    ProjectId ProjectId
+) : DomainEvent;

colaflow-api/src/ColaFlow.Domain/Events/ProjectCreatedEvent.cs

@@ -0,0 +1,12 @@
+using ColaFlow.Domain.ValueObjects;
+
+namespace ColaFlow.Domain.Events;
+
+/// <summary>
+/// Event raised when a project is created
+/// </summary>
+public sealed record ProjectCreatedEvent(
+    ProjectId ProjectId,
+    string ProjectName,
+    UserId CreatedBy
+) : DomainEvent;

colaflow-api/src/ColaFlow.Domain/Events/ProjectUpdatedEvent.cs

@@ -0,0 +1,12 @@
+using ColaFlow.Domain.ValueObjects;
+
+namespace ColaFlow.Domain.Events;
+
+/// <summary>
+/// Event raised when a project is updated
+/// </summary>
+public sealed record ProjectUpdatedEvent(
+    ProjectId ProjectId,
+    string Name,
+    string Description
+) : DomainEvent;

colaflow-api/src/ColaFlow.Domain/Exceptions/DomainException.cs

@@ -0,0 +1,18 @@
+namespace ColaFlow.Domain.Exceptions;
+
+/// <summary>
+/// Exception type for domain layer
+/// </summary>
+public class DomainException : Exception
+{
+    public DomainException()
+    { }
+
+    public DomainException(string message)
+        : base(message)
+    { }
+
+    public DomainException(string message, Exception innerException)
+        : base(message, innerException)
+    { }
+}

colaflow-api/src/ColaFlow.Domain/ValueObjects/EpicId.cs

@@ -0,0 +1,26 @@
+using ColaFlow.Domain.Common;
+
+namespace ColaFlow.Domain.ValueObjects;
+
+/// <summary>
+/// EpicId Value Object (strongly-typed ID)
+/// </summary>
+public sealed class EpicId : ValueObject
+{
+    public Guid Value { get; private set; }
+
+    private EpicId(Guid value)
+    {
+        Value = value;
+    }
+
+    public static EpicId Create() => new EpicId(Guid.NewGuid());
+    public static EpicId Create(Guid value) => new EpicId(value);
+
+    protected override IEnumerable<object> GetAtomicValues()
+    {
+        yield return Value;
+    }
+
+    public override string ToString() => Value.ToString();
+}

colaflow-api/src/ColaFlow.Domain/ValueObjects/ProjectId.cs

@@ -0,0 +1,26 @@
+using ColaFlow.Domain.Common;
+
+namespace ColaFlow.Domain.ValueObjects;
+
+/// <summary>
+/// ProjectId Value Object (strongly-typed ID)
+/// </summary>
+public sealed class ProjectId : ValueObject
+{
+    public Guid Value { get; private set; }
+
+    private ProjectId(Guid value)
+    {
+        Value = value;
+    }
+
+    public static ProjectId Create() => new ProjectId(Guid.NewGuid());
+    public static ProjectId Create(Guid value) => new ProjectId(value);
+
+    protected override IEnumerable<object> GetAtomicValues()
+    {
+        yield return Value;
+    }
+
+    public override string ToString() => Value.ToString();
+}

colaflow-api/src/ColaFlow.Domain/ValueObjects/ProjectKey.cs

@@ -0,0 +1,38 @@
+using ColaFlow.Domain.Common;
+using ColaFlow.Domain.Exceptions;
+
+namespace ColaFlow.Domain.ValueObjects;
+
+/// <summary>
+/// ProjectKey Value Object (e.g., "COLA", "FLOW")
+/// </summary>
+public sealed class ProjectKey : ValueObject
+{
+    public string Value { get; private set; }
+
+    private ProjectKey(string value)
+    {
+        Value = value;
+    }
+
+    public static ProjectKey Create(string value)
+    {
+        if (string.IsNullOrWhiteSpace(value))
+            throw new DomainException("Project key cannot be empty");
+
+        if (value.Length > 10)
+            throw new DomainException("Project key cannot exceed 10 characters");
+
+        if (!System.Text.RegularExpressions.Regex.IsMatch(value, "^[A-Z0-9]+$"))
+            throw new DomainException("Project key must contain only uppercase letters and numbers");
+
+        return new ProjectKey(value);
+    }
+
+    protected override IEnumerable<object> GetAtomicValues()
+    {
+        yield return Value;
+    }
+
+    public override string ToString() => Value;
+}

colaflow-api/src/ColaFlow.Domain/ValueObjects/ProjectStatus.cs

@@ -0,0 +1,17 @@
+using ColaFlow.Domain.Common;
+
+namespace ColaFlow.Domain.ValueObjects;
+
+/// <summary>
+/// ProjectStatus Enumeration
+/// </summary>
+public sealed class ProjectStatus : Enumeration
+{
+    public static readonly ProjectStatus Active = new(1, "Active");
+    public static readonly ProjectStatus Archived = new(2, "Archived");
+    public static readonly ProjectStatus OnHold = new(3, "On Hold");
+
+    private ProjectStatus(int id, string name) : base(id, name)
+    {
+    }
+}

colaflow-api/src/ColaFlow.Domain/ValueObjects/StoryId.cs

@@ -0,0 +1,26 @@
+using ColaFlow.Domain.Common;
+
+namespace ColaFlow.Domain.ValueObjects;
+
+/// <summary>
+/// StoryId Value Object (strongly-typed ID)
+/// </summary>
+public sealed class StoryId : ValueObject
+{
+    public Guid Value { get; private set; }
+
+    private StoryId(Guid value)
+    {
+        Value = value;
+    }
+
+    public static StoryId Create() => new StoryId(Guid.NewGuid());
+    public static StoryId Create(Guid value) => new StoryId(value);
+
+    protected override IEnumerable<object> GetAtomicValues()
+    {
+        yield return Value;
+    }
+
+    public override string ToString() => Value.ToString();
+}

colaflow-api/src/ColaFlow.Domain/ValueObjects/TaskId.cs

@@ -0,0 +1,26 @@
+using ColaFlow.Domain.Common;
+
+namespace ColaFlow.Domain.ValueObjects;
+
+/// <summary>
+/// TaskId Value Object (strongly-typed ID)
+/// </summary>
+public sealed class TaskId : ValueObject
+{
+    public Guid Value { get; private set; }
+
+    private TaskId(Guid value)
+    {
+        Value = value;
+    }
+
+    public static TaskId Create() => new TaskId(Guid.NewGuid());
+    public static TaskId Create(Guid value) => new TaskId(value);
+
+    protected override IEnumerable<object> GetAtomicValues()
+    {
+        yield return Value;
+    }
+
+    public override string ToString() => Value.ToString();
+}

colaflow-api/src/ColaFlow.Domain/ValueObjects/TaskPriority.cs

@@ -0,0 +1,18 @@
+using ColaFlow.Domain.Common;
+
+namespace ColaFlow.Domain.ValueObjects;
+
+/// <summary>
+/// TaskPriority Enumeration
+/// </summary>
+public sealed class TaskPriority : Enumeration
+{
+    public static readonly TaskPriority Low = new(1, "Low");
+    public static readonly TaskPriority Medium = new(2, "Medium");
+    public static readonly TaskPriority High = new(3, "High");
+    public static readonly TaskPriority Urgent = new(4, "Urgent");
+
+    private TaskPriority(int id, string name) : base(id, name)
+    {
+    }
+}

colaflow-api/src/ColaFlow.Domain/ValueObjects/UserId.cs

@@ -0,0 +1,26 @@
+using ColaFlow.Domain.Common;
+
+namespace ColaFlow.Domain.ValueObjects;
+
+/// <summary>
+/// UserId Value Object (strongly-typed ID)
+/// </summary>
+public sealed class UserId : ValueObject
+{
+    public Guid Value { get; private set; }
+
+    private UserId(Guid value)
+    {
+        Value = value;
+    }
+
+    public static UserId Create() => new UserId(Guid.NewGuid());
+    public static UserId Create(Guid value) => new UserId(value);
+
+    protected override IEnumerable<object> GetAtomicValues()
+    {
+        yield return Value;
+    }
+
+    public override string ToString() => Value.ToString();
+}

colaflow-api/src/ColaFlow.Domain/ValueObjects/WorkItemStatus.cs

@@ -0,0 +1,19 @@
+using ColaFlow.Domain.Common;
+
+namespace ColaFlow.Domain.ValueObjects;
+
+/// <summary>
+/// WorkItemStatus Enumeration (renamed from TaskStatus to avoid conflict with System.Threading.Tasks.TaskStatus)
+/// </summary>
+public sealed class WorkItemStatus : Enumeration
+{
+    public static readonly WorkItemStatus ToDo = new(1, "To Do");
+    public static readonly WorkItemStatus InProgress = new(2, "In Progress");
+    public static readonly WorkItemStatus InReview = new(3, "In Review");
+    public static readonly WorkItemStatus Done = new(4, "Done");
+    public static readonly WorkItemStatus Blocked = new(5, "Blocked");
+
+    private WorkItemStatus(int id, string name) : base(id, name)
+    {
+    }
+}