Implement core IRC channel functionality:
1. Channel member flags: is_operator and is_voiced columns in
channel_members table (proper boolean columns per sneak's
instruction, not text string modes).
2. MODE +o/+v/-o/-v: Grant/revoke operator and voice status.
Permission-checked (only +o can grant). NAMES replies show
@nick for operators and +nick for voiced users.
3. MODE +m (moderated): Only +o and +v users can send PRIVMSG
or NOTICE to moderated channels. Others get ERR_CANNOTSENDTOCHAN.
4. MODE +t (topic lock): Only +o can change topic when active.
Default ON for new channels (standard IRC behavior). Others
get ERR_CHANOPRIVSNEEDED.
5. KICK command: Operator-only, removes user from channel,
broadcasts to all members including kicked user.
6. NOTICE differentiation: No RPL_AWAY auto-reply, skips hashcash
validation on +H channels per RFC 2812.
Additional improvements:
- Channel creator auto-gets +o on first JOIN
- ISUPPORT now advertises PREFIX=(ov)@+ and CHANMODES=,,H,mnst
- MODE query shows accurate +nt/+m/+H mode string
- Fixed pre-existing unparam lint issue in fanOutSilent
Includes 22 new tests covering all requirements.
closes#85
