feat: Add IRC gateway functionality and update documentation

docs/api/core-articles/index.md

@@ -5,5 +5,5 @@ Articles related to the EchoHub.Core shared library.
 ## Topics
 
 - Data models and DTOs
-- SignalR contract interface
+- Contract interfaces (IChatService, IChatBroadcaster, IEchoHubClient)
 - Validation constants and shared rules

docs/api/index.md

@@ -10,8 +10,12 @@ Terminal.Gui v2 TUI application -- UI components, services, themes, and configur
 
 ### Core
 
-Shared library -- DTOs, models, constants, and the SignalR client contract.
+Shared library -- DTOs, models, constants, and contracts (`IChatService`, `IChatBroadcaster`, `IEchoHubClient`).
 
 ### Server
 
-ASP.NET Core server -- controllers, hubs, authentication, and data access.
+ASP.NET Core server -- controllers, hubs, ChatService, SignalRBroadcaster, authentication, and data access.
+
+### Server.Irc
+
+IRC protocol gateway -- TCP listener, command handler, IrcBroadcaster, and message formatter.

docs/api/server-articles/index.md

@@ -6,6 +6,8 @@ Articles related to the EchoHub server built with ASP.NET Core.
 
 - Authentication and JWT tokens
 - SignalR hub and real-time messaging
+- IRC gateway and protocol bridging
+- ChatService and broadcaster pattern
 - File upload and validation
 - Rate limiting configuration
 - Database schema and migrations

docs/api/toc.yml

@@ -16,3 +16,7 @@
       href: ../_api_meta/server/toc.yml
     - name: Articles
       href: server-articles/
+- name: Server.Irc
+  items:
+    - name: API Reference
+      href: ../_api_meta/server-irc/toc.yml