SiteBot now respects server-assigned nickname (e.g. NICKLEN truncation)

[tsautier]

Problem

SiteBot's getNick() method returns the configured nickname rather than the actual IRC nickname assigned by the server. When the IRC server has a NICKLEN limit (e.g., 9 characters), the bot's actual name gets truncated but the code doesn't reflect this.

Solution

Update getNick() to return the actual IRC nickname after connection, accounting for server-imposed length limits.

Changes Made

• Modified SiteBot.java to track and return the actual nickname assigned by the server
• Nickname now correctly reflects IRC server NICKLEN restrictions

Fixes: #190

[tsautier]

@mvangoor @hrxcodes for review