✨ Add chat message handling and WebSocket integration

Introduce new `ChatService` for managing chat messages, including marking messages as read and checking read status. Add `WebSocketPacket` class for handling WebSocket communication and integrate it with `WebSocketService` to process chat-related packets. Enhance `ChatRoom` and `ChatMember` models with additional fields and relationships. Update `AppDatabase` to include new chat-related entities and adjust permissions for chat creation.

DysonNetwork.Sphere/Chat/ChatService.cs

@@ -0,0 +1,48 @@
+using DysonNetwork.Sphere;
+using DysonNetwork.Sphere.Chat;
+using Microsoft.EntityFrameworkCore;
+
+public class ChatService(AppDatabase db)
+{
+    public async Task MarkMessageAsReadAsync(Guid messageId, long roomId, long userId)
+    {
+        var existingStatus = await db.ChatStatuses
+            .FirstOrDefaultAsync(x => x.MessageId == messageId && x.Sender.AccountId == userId);
+        var sender = await db.ChatMembers
+            .Where(m => m.AccountId == userId && m.ChatRoomId == roomId)
+            .FirstOrDefaultAsync();
+        if (sender is null) throw new ArgumentException("User is not a member of the chat room.");
+
+        if (existingStatus == null)
+        {
+            existingStatus = new MessageStatus
+            {
+                MessageId = messageId,
+                SenderId = sender.Id,
+            };
+            db.ChatStatuses.Add(existingStatus);
+        }
+
+        await db.SaveChangesAsync();
+    }
+
+    public async Task<bool> GetMessageReadStatus(Guid messageId, long userId)
+    {
+        return await db.ChatStatuses
+            .AnyAsync(x => x.MessageId == messageId && x.Sender.AccountId == userId);
+    }
+
+    public async Task<int> CountUnreadMessage(long userId, long chatRoomId)
+    {
+        var messages = await db.ChatMessages
+            .Where(m => m.ChatRoomId == chatRoomId)
+            .Select(m => new MessageStatusResponse
+            {
+                MessageId = m.Id,
+                IsRead = m.Statuses.Any(rs => rs.Sender.AccountId == userId)
+            })
+            .ToListAsync();
+
+        return messages.Count(m => !m.IsRead);
+    }
+}