fix: rebase onto main, add IRC wire handlers and integration tests for Tier 3 commands

Rebase onto main to resolve conflicts from module path rename
(sneak.berlin/go/neoirc) and integration test addition.

- Update import paths in utility.go to new module path
- Add IRC wire protocol handlers for VERSION, ADMIN, INFO,
  TIME, KILL, and WALLOPS to ircserver/commands.go
- Register all 6 new commands in the IRC command dispatch map
- Implement proper user MODE +w/-w support for WALLOPS
- Add WALLOPS relay delivery in relay.go
- Add integration tests for all 7 Tier 3 commands:
  USERHOST, VERSION, ADMIN, INFO, TIME, KILL, WALLOPS
- Add newTestEnvWithOper helper for oper-dependent tests

internal/ircserver/relay.go

@@ -120,6 +120,8 @@ func (c *Conn) deliverIRCMessage(
 		c.deliverKickMsg(msg, text)
 	case command == "INVITE":
 		c.deliverInviteMsg(msg, text)
+	case command == irc.CmdWallops:
+		c.deliverWallops(msg, text)
 	case command == irc.CmdMode:
 		c.deliverMode(msg, text)
 	case command == irc.CmdPing:
@@ -305,6 +307,18 @@ func (c *Conn) deliverInviteMsg(
 	c.sendFromServer("NOTICE", c.nick, text)
 }
 
+// deliverWallops sends a WALLOPS notification.
+func (c *Conn) deliverWallops(
+	msg *db.IRCMessage,
+	text string,
+) {
+	prefix := msg.From + "!" + msg.From + "@*"
+
+	c.send(FormatMessage(
+		prefix, irc.CmdWallops, text,
+	))
+}
+
 // deliverMode sends a MODE change notification.
 func (c *Conn) deliverMode(
 	msg *db.IRCMessage,