✨ Implement realtime chat

DysonNetwork.Sphere/Chat/Realtime/IRealtimeService.cs

@@ -0,0 +1,56 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+namespace DysonNetwork.Sphere.Chat.Realtime;
+
+/// <summary>
+/// Interface for real-time communication services (like Cloudflare, Agora, Twilio, etc.)
+/// </summary>
+public interface IRealtimeService
+{
+    /// <summary>
+    /// Service provider name
+    /// </summary>
+    string ProviderName { get; }
+    
+    /// <summary>
+    /// Creates a new real-time session
+    /// </summary>
+    /// <param name="roomId">The room identifier</param>
+    /// <param name="metadata">Additional metadata to associate with the session</param>
+    /// <returns>Session configuration data</returns>
+    Task<RealtimeSessionConfig> CreateSessionAsync(Guid roomId, Dictionary<string, object> metadata);
+    
+    /// <summary>
+    /// Ends an existing real-time session
+    /// </summary>
+    /// <param name="sessionId">The session identifier</param>
+    /// <param name="config">The session configuration</param>
+    Task EndSessionAsync(string sessionId, RealtimeSessionConfig config);
+
+    /// <summary>
+    /// Gets a token for user to join the session
+    /// </summary>
+    /// <param name="account">The user identifier</param>
+    /// <param name="sessionId">The session identifier</param>
+    /// <param name="isAdmin">The user is the admin of session</param>
+    /// <returns>User-specific token for the session</returns>
+    string GetUserToken(Account.Account account, string sessionId, bool isAdmin = false);
+}
+
+/// <summary>
+/// Common configuration object for real-time sessions
+/// </summary>
+public class RealtimeSessionConfig
+{
+    /// <summary>
+    /// Service-specific session identifier
+    /// </summary>
+    public string SessionId { get; set; } = null!;
+    
+    /// <summary>
+    /// Additional provider-specific configuration parameters
+    /// </summary>
+    public Dictionary<string, object> Parameters { get; set; } = new();
+}