Add 30-second timeout after WebSocket opens to detect when Discord
never sends HELLO (zombie state). If isConnected stays false after
timeout, forces a fresh connection instead of hanging indefinitely.
Relates to #595
Add listener for Carbon GatewayPlugin 'debug' events to capture WebSocket
connection state changes. Critical events (close, reconnect, resume) are
logged at INFO level always; all debug messages logged in verbose mode.
Fixes#595