v0.2.0 - IRC Gateway

Features

IRC protocol gateway -- native IRC clients (irssi, WeeChat, HexChat, etc.) can connect to EchoHub servers
Cross-protocol messaging -- messages flow bidirectionally between IRC and TUI clients in real time
SASL PLAIN authentication -- IRC clients can authenticate via SASL or traditional PASS/NICK/USER
Full IRC command support -- JOIN, PART, PRIVMSG, QUIT, NAMES, TOPIC, WHO, WHOIS, AWAY, LIST, MODE, MOTD
TLS support -- optional encrypted IRC connections on port 6697
Image-to-IRC formatting -- images appear as ASCII art line-by-line with download URLs
Message splitting -- long messages automatically split at word boundaries (~400 byte chunks)
Configurable MOTD -- server message of the day for IRC clients

Extracted shared business logic from ChatHub into protocol-agnostic IChatService
Introduced IChatBroadcaster pattern for multi-protocol event fan-out
ChatHub refactored to thin adapter delegating to IChatService
ChannelsController updated to use IChatService for broadcasts
New EchoHub.Server.Irc project for clean separation of concerns
IChatService and IChatBroadcaster interfaces live in EchoHub.Core/Contracts