Add hex color parsing helper and implement custom list sources for channels and users

- Introduced HexColorHelper for parsing hex color strings to Terminal.Gui Attributes and Colors.
- Created ChannelListSource for managing and rendering a list of channels with unread counts and active indicators.
- Developed UserListSource for displaying online users with per-user nickname colors.
- Refactored MainWindow to utilize ChatMessageManager for handling messages and channel state.
- Updated project references and removed unused content from the server project.
- Adjusted tests to reflect changes in namespaces and structure.

src/EchoHub.Client/Services/AsyncRunner.cs

@@ -0,0 +1,32 @@
+using Serilog;
+using Terminal.Gui.App;
+
+namespace EchoHub.Client.Services;
+
+/// <summary>
+/// Eliminates repeated Task.Run/try/catch/app.Invoke(ShowError) boilerplate.
+/// Runs async work on a background thread and routes exceptions to the UI.
+/// </summary>
+public static class AsyncRunner
+{
+    public static void Run(
+        IApplication app,
+        Func<Task> work,
+        Action<string> showError,
+        string errorPrefix,
+        string? logContext = null)
+    {
+        Task.Run(async () =>
+        {
+            try
+            {
+                await work();
+            }
+            catch (Exception ex)
+            {
+                Log.Error(ex, "{Context} failed", logContext ?? errorPrefix);
+                app.Invoke(() => showError($"{errorPrefix}: {ex.Message}"));
+            }
+        });
+    }
+}

src/EchoHub.Client/Services/AvatarHelper.cs

@@ -0,0 +1,44 @@
+using Serilog;
+
+namespace EchoHub.Client.Services;
+
+/// <summary>
+/// Shared avatar upload logic — resolves a file path or URL to a stream
+/// and uploads it via ApiClient.
+/// </summary>
+internal static class AvatarHelper
+{
+    /// <summary>
+    /// Upload an avatar from a local file path or HTTP(S) URL.
+    /// Returns the ASCII art response from the server.
+    /// </summary>
+    public static async Task<string?> UploadAsync(ApiClient apiClient, string target)
+    {
+        Stream stream;
+        string fileName;
+
+        if (Uri.TryCreate(target, UriKind.Absolute, out var uri)
+            && (uri.Scheme == "http" || uri.Scheme == "https"))
+        {
+            using var http = new HttpClient();
+            var bytes = await http.GetByteArrayAsync(uri);
+            stream = new MemoryStream(bytes);
+            fileName = Path.GetFileName(uri.LocalPath);
+            if (string.IsNullOrWhiteSpace(fileName) || !fileName.Contains('.'))
+                fileName = "avatar.png";
+        }
+        else
+        {
+            if (!File.Exists(target))
+                throw new FileNotFoundException($"File not found: {target}");
+
+            stream = File.OpenRead(target);
+            fileName = Path.GetFileName(target);
+        }
+
+        await using (stream)
+        {
+            return await apiClient.UploadAvatarAsync(stream, fileName);
+        }
+    }
+}

src/EchoHub.Client/Services/ConnectionManager.cs

@@ -0,0 +1,268 @@
+using EchoHub.Client.Config;
+using EchoHub.Client.UI.Dialogs;
+using EchoHub.Core.Constants;
+using EchoHub.Core.DTOs;
+using EchoHub.Core.Models;
+using Serilog;
+
+namespace EchoHub.Client.Services;
+
+/// <summary>
+/// Result of a successful connection, returned to AppOrchestrator for UI updates.
+/// </summary>
+internal record ConnectResult(
+    LoginResponse Login,
+    List<ChannelDto> Channels,
+    List<MessageDto> DefaultHistory);
+
+/// <summary>
+/// Owns connection lifecycle, authentication, SignalR event wiring, and channel tracking.
+/// Fires events so AppOrchestrator can update the UI without managing connection internals.
+/// </summary>
+internal sealed class ConnectionManager : IAsyncDisposable
+{
+    private EchoHubConnection? _connection;
+    private ApiClient? _apiClient;
+    private readonly ClientEncryptionService _encryption = new();
+    private readonly HashSet<string> _joinedChannels = [];
+
+    // ── Properties ────────────────────────────────────────────────────────
+
+    public bool IsConnected => _connection?.IsConnected == true;
+    public bool IsAuthenticated => _apiClient is not null;
+    public ApiClient? Api => _apiClient;
+
+    // ── Events (forwarded from SignalR) ───────────────────────────────────
+
+    public event Action<MessageDto>? MessageReceived;
+    public event Action<string, string>? UserJoined;
+    public event Action<string, string>? UserLeft;
+    public event Action<UserPresenceDto>? UserStatusChanged;
+    public event Action<string, string, string?>? UserKicked;
+    public event Action<string, string?>? UserBanned;
+    public event Action<string>? ForceDisconnected;
+    public event Action<string, Guid>? MessageDeleted;
+    public event Action<string>? ChannelNuked;
+    public event Action<ChannelDto>? ChannelUpdated;
+    public event Action<string>? Error;
+    public event Action<string>? ConnectionStatusChanged;
+    public event Action? Reconnected;
+
+    // ── Connect ───────────────────────────────────────────────────────────
+
+    /// <summary>
+    /// Full connection flow: authenticate → encryption → SignalR → join default channel.
+    /// Calls <paramref name="onStatus"/> with progress messages for UI updates.
+    /// Throws on auth failure (caller handles saved-session expiry, etc.).
+    /// </summary>
+    public async Task<ConnectResult> ConnectAsync(ConnectDialogResult info, Action<string> onStatus)
+    {
+        _apiClient?.Dispose();
+        _apiClient = new ApiClient(info.ServerUrl);
+
+        onStatus("Authenticating...");
+
+        LoginResponse loginResponse;
+
+        if (info.SavedRefreshToken is not null)
+        {
+            try
+            {
+                loginResponse = await _apiClient.LoginWithRefreshTokenAsync(info.SavedRefreshToken);
+                Log.Information("Authenticated via saved session for {User}", loginResponse.Username);
+            }
+            catch
+            {
+                _apiClient.Dispose();
+                _apiClient = null;
+                throw; // Caller handles saved-session expiry
+            }
+        }
+        else if (info.IsRegister)
+        {
+            loginResponse = await _apiClient.RegisterAsync(info.Username, info.Password);
+        }
+        else
+        {
+            loginResponse = await _apiClient.LoginAsync(info.Username, info.Password);
+        }
+
+        // Auto-persist rotated refresh tokens for Remember Me
+        _apiClient.OnTokensRefreshed += HandleTokensRefreshed;
+
+        // E2E encryption key
+        onStatus("Fetching encryption key...");
+        try
+        {
+            var encryptionKey = await _apiClient.GetEncryptionKeyAsync();
+            _encryption.SetKey(encryptionKey);
+            Log.Information("E2E encryption key established");
+        }
+        catch (Exception ex)
+        {
+            Log.Warning(ex, "Failed to fetch encryption key — messages will not be encrypted");
+        }
+
+        onStatus("Authenticated, connecting...");
+
+        if (_connection is not null)
+            await _connection.DisposeAsync();
+
+        _connection = new EchoHubConnection(info.ServerUrl, _apiClient, _encryption);
+        WireConnectionEvents(_connection);
+        await _connection.ConnectAsync();
+
+        var channels = await _apiClient.GetChannelsAsync();
+        onStatus("Connected");
+
+        // Join default channel + fetch history
+        _joinedChannels.Clear();
+        _joinedChannels.Add(HubConstants.DefaultChannel);
+        await _connection.JoinChannelAsync(HubConstants.DefaultChannel);
+
+        List<MessageDto> history = [];
+        try
+        {
+            history = await _connection.GetHistoryAsync(HubConstants.DefaultChannel);
+        }
+        catch
+        {
+            // History might not be available
+        }
+
+        return new ConnectResult(loginResponse, channels, history);
+    }
+
+    // ── Cleanup ───────────────────────────────────────────────────────────
+
+    /// <summary>
+    /// Disconnect and dispose connection + API client, clear channel tracking.
+    /// </summary>
+    public async Task CleanupAsync()
+    {
+        if (_connection is not null)
+        {
+            await _connection.DisconnectAsync();
+            await _connection.DisposeAsync();
+            _connection = null;
+        }
+
+        _apiClient?.Dispose();
+        _apiClient = null;
+        _joinedChannels.Clear();
+    }
+
+    /// <summary>
+    /// Revoke refresh token on the server. Call <see cref="CleanupAsync"/> afterwards.
+    /// </summary>
+    public async Task LogoutAsync()
+    {
+        if (_apiClient is not null)
+            await _apiClient.LogoutAsync();
+    }
+
+    // ── Channel Operations ────────────────────────────────────────────────
+
+    public async Task<List<MessageDto>> JoinChannelAsync(string channelName)
+    {
+        if (_connection is null) throw new InvalidOperationException("Not connected");
+        _joinedChannels.Add(channelName);
+        return await _connection.JoinChannelAsync(channelName);
+    }
+
+    public async Task LeaveChannelAsync(string channelName)
+    {
+        if (_connection is null) throw new InvalidOperationException("Not connected");
+        await _connection.LeaveChannelAsync(channelName);
+        _joinedChannels.Remove(channelName);
+    }
+
+    /// <summary>
+    /// Track a channel as joined (returns true if newly added).
+    /// </summary>
+    public bool TrackChannel(string channelName) => _joinedChannels.Add(channelName);
+
+    public void UntrackChannel(string channelName) => _joinedChannels.Remove(channelName);
+
+    // ── Delegate Operations ───────────────────────────────────────────────
+
+    public Task SendMessageAsync(string channel, string content) =>
+        _connection?.SendMessageAsync(channel, content)
+        ?? throw new InvalidOperationException("Not connected");
+
+    public Task<List<MessageDto>> GetHistoryAsync(string channel) =>
+        _connection?.GetHistoryAsync(channel)
+        ?? throw new InvalidOperationException("Not connected");
+
+    public Task<List<UserPresenceDto>> GetOnlineUsersAsync(string channel) =>
+        _connection?.GetOnlineUsersAsync(channel)
+        ?? throw new InvalidOperationException("Not connected");
+
+    public Task UpdateStatusAsync(UserStatus status, string? message) =>
+        _connection?.UpdateStatusAsync(status, message)
+        ?? throw new InvalidOperationException("Not connected");
+
+    // ── Reconnect ─────────────────────────────────────────────────────────
+
+    /// <summary>
+    /// Rejoin all previously tracked channels after a reconnect.
+    /// </summary>
+    public async Task RejoinChannelsAsync()
+    {
+        var channels = _joinedChannels.ToList();
+        if (channels.Count == 0 || _connection is null) return;
+
+        _joinedChannels.Clear();
+
+        foreach (var channel in channels)
+        {
+            _joinedChannels.Add(channel);
+            await _connection.JoinChannelAsync(channel);
+        }
+
+        Log.Information("Rejoined {Count} channel(s) after reconnect", channels.Count);
+    }
+
+    // ── SignalR Event Wiring ──────────────────────────────────────────────
+
+    private void WireConnectionEvents(EchoHubConnection connection)
+    {
+        connection.OnMessageReceived += msg => MessageReceived?.Invoke(msg);
+        connection.OnUserJoined += (ch, user) => UserJoined?.Invoke(ch, user);
+        connection.OnUserLeft += (ch, user) => UserLeft?.Invoke(ch, user);
+        connection.OnUserStatusChanged += p => UserStatusChanged?.Invoke(p);
+        connection.OnUserKicked += (ch, user, reason) => UserKicked?.Invoke(ch, user, reason);
+        connection.OnUserBanned += (user, reason) => UserBanned?.Invoke(user, reason);
+        connection.OnForceDisconnect += reason => ForceDisconnected?.Invoke(reason);
+        connection.OnMessageDeleted += (ch, id) => MessageDeleted?.Invoke(ch, id);
+        connection.OnChannelNuked += ch => ChannelNuked?.Invoke(ch);
+        connection.OnChannelUpdated += ch => ChannelUpdated?.Invoke(ch);
+        connection.OnError += msg => Error?.Invoke(msg);
+        connection.OnConnectionStateChanged += status => ConnectionStatusChanged?.Invoke(status);
+        connection.OnReconnected += () => Reconnected?.Invoke();
+    }
+
+    // ── Token Persistence ─────────────────────────────────────────────────
+
+    private void HandleTokensRefreshed()
+    {
+        if (_apiClient?.RefreshToken is null) return;
+        var config = ConfigManager.Load();
+        var server = config.SavedServers.FirstOrDefault(s =>
+            string.Equals(s.Url, _apiClient.BaseUrl, StringComparison.OrdinalIgnoreCase));
+        if (server is not null && server.RememberMe)
+        {
+            server.RefreshToken = _apiClient.RefreshToken;
+            ConfigManager.Save(config);
+        }
+    }
+
+    // ── Dispose ───────────────────────────────────────────────────────────
+
+    public async ValueTask DisposeAsync()
+    {
+        _apiClient?.Dispose();
+        if (_connection is not null)
+            await _connection.DisposeAsync();
+    }
+}

src/EchoHub.Client/Services/UpdateChecker.cs

@@ -1,6 +1,6 @@
 using AlwaysUpToDate;
 
-using EchoHub.Client.UI;
+using EchoHub.Client.UI.Dialogs;
 
 using Serilog;
 

src/EchoHub.Client/Services/UserSession.cs

@@ -0,0 +1,20 @@
+using EchoHub.Core.Models;
+
+namespace EchoHub.Client.Services;
+
+/// <summary>
+/// Holds the current user's session state (username, status, status message).
+/// </summary>
+internal sealed class UserSession
+{
+    public string Username { get; set; } = string.Empty;
+    public UserStatus Status { get; set; } = UserStatus.Online;
+    public string? StatusMessage { get; set; }
+
+    public void Reset()
+    {
+        Username = string.Empty;
+        Status = UserStatus.Online;
+        StatusMessage = null;
+    }
+}