feat: enhance profile editing with avatar support and UI adjustments

- Added AvatarPath to ProfileEditResult for user profile updates.
- Updated ProfileEditDialog to include avatar selection with a browse button.
- Increased dialog height to accommodate new avatar input fields.
- Implemented avatar file path handling in the profile edit dialog.

feat: introduce moderation features and user roles

- Added ServerRole enum to define user roles (Member, Mod, Admin, Owner).
- Extended User model to include role, mute, and ban status.
- Created ModerationController for user role assignment, kicking, banning, and muting.
- Implemented methods in IChatBroadcaster and SignalRBroadcaster for user moderation actions.
- Updated database schema with new columns for user roles and moderation states.

fix: ensure muted users cannot send messages

- Added mute status checks in ChatService to prevent message sending for muted users.
- Updated user presence and status handling to reflect role changes and moderation actions.

chore: update constants for ASCII art rendering

- Introduced AsciiArtHeightHalfBlock constant for improved ASCII art rendering.

src/EchoHub.Server/Services/ChatService.cs

@@ -72,7 +72,8 @@ public class ChatService : IChatService
                     user.DisplayName,
                     user.NicknameColor,
                     UserStatus.Invisible,
-                    user.StatusMessage);
+                    user.StatusMessage,
+                    user.Role);
 
                 await BroadcastToAllAsync(b => b.SendUserStatusChangedAsync(channelsBeforeDisconnect, presence));
             }
@@ -139,6 +140,21 @@ public class ChatService : IChatService
 
         var sender = await db.Users.FindAsync(userId);
 
+        // Check mute status
+        if (sender is not null && sender.IsMuted)
+        {
+            if (sender.MutedUntil.HasValue && sender.MutedUntil.Value <= DateTimeOffset.UtcNow)
+            {
+                sender.IsMuted = false;
+                sender.MutedUntil = null;
+                await db.SaveChangesAsync();
+            }
+            else
+            {
+                return "You are muted and cannot send messages.";
+            }
+        }
+
         var message = new Message
         {
             Id = Guid.NewGuid(),
@@ -203,7 +219,8 @@ public class ChatService : IChatService
             user.DisplayName,
             user.NicknameColor,
             status,
-            statusMessage);
+            statusMessage,
+            user.Role);
 
         var channels = _presenceTracker.GetChannelsForUser(username);
         await BroadcastToAllAsync(b => b.SendUserStatusChangedAsync(channels, presence));
@@ -226,7 +243,8 @@ public class ChatService : IChatService
                 u.DisplayName,
                 u.NicknameColor,
                 u.Status,
-                u.StatusMessage))
+                u.StatusMessage,
+                u.Role))
             .ToListAsync();
     }
 
@@ -264,7 +282,7 @@ public class ChatService : IChatService
         return new UserProfileDto(
             user.Id, user.Username, user.DisplayName, user.Bio,
             user.NicknameColor, user.AvatarAscii, user.Status,
-            user.StatusMessage, user.CreatedAt, user.LastSeenAt);
+            user.StatusMessage, user.Role, user.CreatedAt, user.LastSeenAt);
     }
 
     public async Task<(string? Topic, bool Exists)> GetChannelTopicAsync(string channelName)

src/EchoHub.Server/Services/ImageToAsciiService.cs

@@ -8,47 +8,72 @@ namespace EchoHub.Server.Services;
 
 public class ImageToAsciiService
 {
-    private static readonly char[] AsciiChars = " .:-=+*#%@".ToCharArray();
-
-    public string ConvertToAscii(Stream imageStream, int width = HubConstants.AsciiArtWidth, int height = HubConstants.AsciiArtHeight)
+    /// <summary>
+    /// Converts an image to ASCII art using half-block characters (▀▄█) with
+    /// 24-bit ANSI foreground and background colors for 2x vertical resolution.
+    /// Each character cell represents two vertical pixels.
+    /// </summary>
+    public string ConvertToAscii(Stream imageStream, int width = HubConstants.AsciiArtWidth, int height = HubConstants.AsciiArtHeightHalfBlock)
     {
         using var image = Image.Load<Rgba32>(imageStream);
 
+        // Ensure height is even for pair processing
+        if (height % 2 != 0) height++;
+
         image.Mutate(x => x.Resize(width, height));
 
         var sb = new StringBuilder();
 
-        byte lastR = 0, lastG = 0, lastB = 0;
-        bool hasLastColor = false;
-
-        for (int y = 0; y < image.Height; y++)
+        for (int y = 0; y < image.Height; y += 2)
         {
+            byte lastFgR = 0, lastFgG = 0, lastFgB = 0;
+            byte lastBgR = 0, lastBgG = 0, lastBgB = 0;
+            bool hasLastColor = false;
+
             for (int x = 0; x < image.Width; x++)
             {
-                var pixel = image[x, y];
-                var brightness = 0.299 * pixel.R + 0.587 * pixel.G + 0.114 * pixel.B;
+                var topPixel = image[x, y];
+                var bottomPixel = (y + 1 < image.Height) ? image[x, y + 1] : topPixel;
 
-                // Map brightness (0-255) to ASCII char index
-                var index = (int)((brightness / 255.0) * (AsciiChars.Length - 1));
+                byte fgR, fgG, fgB, bgR, bgG, bgB;
+                char blockChar;
 
-                // Emit ANSI 24-bit color only when it changes
-                if (!hasLastColor || pixel.R != lastR || pixel.G != lastG || pixel.B != lastB)
+                if (topPixel.R == bottomPixel.R && topPixel.G == bottomPixel.G && topPixel.B == bottomPixel.B)
                 {
-                    sb.Append($"\x1b[38;2;{pixel.R};{pixel.G};{pixel.B}m");
-                    lastR = pixel.R;
-                    lastG = pixel.G;
-                    lastB = pixel.B;
-                    hasLastColor = true;
+                    // Both pixels same color — full block
+                    fgR = topPixel.R; fgG = topPixel.G; fgB = topPixel.B;
+                    bgR = topPixel.R; bgG = topPixel.G; bgB = topPixel.B;
+                    blockChar = '\u2588'; // █
+                }
+                else
+                {
+                    // Top pixel = foreground, bottom pixel = background, upper half block
+                    fgR = topPixel.R; fgG = topPixel.G; fgB = topPixel.B;
+                    bgR = bottomPixel.R; bgG = bottomPixel.G; bgB = bottomPixel.B;
+                    blockChar = '\u2580'; // ▀
                 }
 
-                sb.Append(AsciiChars[index]);
+                // Emit color codes only when they change
+                bool fgChanged = !hasLastColor || fgR != lastFgR || fgG != lastFgG || fgB != lastFgB;
+                bool bgChanged = !hasLastColor || bgR != lastBgR || bgG != lastBgG || bgB != lastBgB;
+
+                if (fgChanged)
+                    sb.Append($"\x1b[38;2;{fgR};{fgG};{fgB}m");
+                if (bgChanged)
+                    sb.Append($"\x1b[48;2;{bgR};{bgG};{bgB}m");
+
+                sb.Append(blockChar);
+
+                lastFgR = fgR; lastFgG = fgG; lastFgB = fgB;
+                lastBgR = bgR; lastBgG = bgG; lastBgB = bgB;
+                hasLastColor = true;
             }
 
             // Reset color at end of line
             sb.Append("\x1b[0m");
             hasLastColor = false;
 
-            if (y < image.Height - 1)
+            if (y + 2 < image.Height)
             {
                 sb.AppendLine();
             }

src/EchoHub.Server/Services/SignalRBroadcaster.cs

@@ -54,6 +54,18 @@ public class SignalRBroadcaster : IChatBroadcaster
         return HubContext.Clients.Clients(connections).UserStatusChanged(presence);
     }
 
+    public Task SendUserKickedAsync(string channelName, string username, string? reason)
+        => HubContext.Clients.Group(channelName).UserKicked(channelName, username, reason);
+
+    public Task SendUserBannedAsync(string username, string? reason)
+        => HubContext.Clients.All.UserBanned(username, reason);
+
+    public Task SendMessageDeletedAsync(string channelName, Guid messageId)
+        => HubContext.Clients.Group(channelName).MessageDeleted(channelName, messageId);
+
+    public Task SendChannelNukedAsync(string channelName)
+        => HubContext.Clients.Group(channelName).ChannelNuked(channelName);
+
     public Task SendErrorAsync(string connectionId, string message)
     {
         if (connectionId.StartsWith("irc-"))