Initial commit: Nexus Mission Control Platform

- ASP.NET Core 10 Backend (JWT Auth, Agent config API)
- Vue 3 Frontend (Dashboard, Team, Agents, Config Editor)
- PostgreSQL Database
- Docker Compose setup
- Mission Control Dashboard redesign

backend/Domain/Entities.cs

@@ -0,0 +1,93 @@
+namespace Nexus.Api.Domain;
+
+public enum OperationalStatus
+{
+    Online,
+    Degraded,
+    Offline,
+    Unknown
+}
+
+/// <summary>
+/// Strongly-typed task lifecycle states.
+/// String values (e.g. "In progress") are preserved for API compatibility
+/// via <see cref="TaskStateHelper"/>; the WorkTask entity continues to store
+/// state as a string in the database.
+/// </summary>
+public enum TaskState
+{
+    Backlog,
+    InProgress,
+    Blocked,
+    Done
+}
+
+public static class TaskStateHelper
+{
+    private static readonly Dictionary<TaskState, string> StateToString = new()
+    {
+        [TaskState.Backlog] = "Backlog",
+        [TaskState.InProgress] = "In progress",
+        [TaskState.Blocked] = "Blocked",
+        [TaskState.Done] = "Done"
+    };
+
+    private static readonly Dictionary<string, TaskState> StringToState = new(StringComparer.OrdinalIgnoreCase)
+    {
+        ["Backlog"] = TaskState.Backlog,
+        ["In progress"] = TaskState.InProgress,
+        ["Blocked"] = TaskState.Blocked,
+        ["Done"] = TaskState.Done
+    };
+
+    /// <summary>Valid task-state string values for API validation.</summary>
+    public static readonly string[] AllStates = ["Backlog", "In progress", "Blocked", "Done"];
+
+    /// <summary>Convert a TaskState enum to its API string representation.</summary>
+    public static string ToStateString(this TaskState state) => StateToString[state];
+
+    /// <summary>Parse a string to TaskState; defaults to Backlog for unrecognized input.</summary>
+    public static TaskState ToTaskState(this string state) =>
+        StringToState.TryGetValue(state, out var result) ? result : TaskState.Backlog;
+
+    /// <summary>Returns true if the string is a recognized task state (case-insensitive).</summary>
+    public static bool IsValidState(string? state) =>
+        !string.IsNullOrWhiteSpace(state) && StringToState.ContainsKey(state);
+
+    public static bool IsInProgressOrBlocked(string? state) =>
+        string.Equals(state, "In progress", StringComparison.OrdinalIgnoreCase)
+        || string.Equals(state, "Blocked", StringComparison.OrdinalIgnoreCase);
+
+    public static bool IsDoneOrBacklog(string? state) =>
+        string.Equals(state, "Done", StringComparison.OrdinalIgnoreCase)
+        || string.Equals(state, "Backlog", StringComparison.OrdinalIgnoreCase);
+}
+
+public sealed class Project
+{
+    public Guid Id { get; init; } = Guid.NewGuid();
+    public required string Name { get; set; }
+    public string Description { get; set; } = string.Empty;
+    public int Progress { get; set; }
+    public OperationalStatus Status { get; set; } = OperationalStatus.Unknown;
+    public DateTimeOffset UpdatedAt { get; set; } = DateTimeOffset.UtcNow;
+}
+
+public sealed class WorkTask
+{
+    public Guid Id { get; init; } = Guid.NewGuid();
+    public required string Title { get; set; }
+    public string State { get; set; } = "Backlog";
+    public string Priority { get; set; } = "Normal";
+    public Guid? ProjectId { get; set; }
+    public DateTimeOffset UpdatedAt { get; set; } = DateTimeOffset.UtcNow;
+}
+
+public sealed class ActivityEvent
+{
+    public long Id { get; init; }
+    public required string Type { get; set; }
+    public required string Message { get; set; }
+    public DateTimeOffset CreatedAt { get; set; } = DateTimeOffset.UtcNow;
+}
+

backend/Domain/Identity.cs

@@ -0,0 +1,45 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace Nexus.Api.Domain;
+
+public class NexusUser
+{
+    public Guid Id { get; set; } = Guid.NewGuid();
+
+    [MaxLength(120)]
+    public string Email { get; set; } = string.Empty;
+
+    [MaxLength(120)]
+    public string NormalizedEmail { get; set; } = string.Empty;
+
+    [MaxLength(100)]
+    public string DisplayName { get; set; } = string.Empty;
+
+    public string PasswordHash { get; set; } = string.Empty;
+
+    public string Role { get; set; } = "owner";
+
+    public DateTimeOffset CreatedAt { get; set; } = DateTimeOffset.UtcNow;
+
+    public DateTimeOffset UpdatedAt { get; set; } = DateTimeOffset.UtcNow;
+
+    public DateTimeOffset? LastLoginAt { get; set; }
+
+    public ICollection<RefreshToken> RefreshTokens { get; set; } = new List<RefreshToken>();
+}
+
+public class RefreshToken
+{
+    public Guid Id { get; set; } = Guid.NewGuid();
+    public Guid UserId { get; set; }
+    [MaxLength(64)]
+    public string TokenHash { get; set; } = string.Empty;
+    public Guid FamilyId { get; set; } = Guid.NewGuid();
+    public DateTimeOffset ExpiresAt { get; set; }
+    public DateTimeOffset CreatedAt { get; set; } = DateTimeOffset.UtcNow;
+    public DateTimeOffset? RevokedAt { get; set; }
+    [MaxLength(64)]
+    public string? ReplacedByTokenHash { get; set; }
+    public Guid ConcurrencyStamp { get; set; } = Guid.NewGuid();
+    public NexusUser User { get; set; } = null!;
+}