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/integration_test.go

@@ -760,6 +760,288 @@ func TestIntegrationTwoClients(t *testing.T) {
 	)
 }
 
+// ── Tier 3 Utility Command Integration Tests ──────────
+
+// TestIntegrationUserhost verifies the USERHOST command
+// returns user@host info for connected nicks.
+func TestIntegrationUserhost(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+
+	alice := env.dial(t)
+	alice.register("alice")
+
+	bob := env.dial(t)
+	bob.register("bob")
+
+	// Query single nick.
+	alice.send("USERHOST bob")
+
+	aliceReply := alice.readUntil(func(l string) bool {
+		return strings.Contains(l, " 302 ")
+	})
+	assertContains(
+		t, aliceReply, " 302 ",
+		"RPL_USERHOST",
+	)
+	assertContains(
+		t, aliceReply, "bob",
+		"USERHOST contains queried nick",
+	)
+
+	// Query multiple nicks.
+	bob.send("USERHOST alice bob")
+
+	bobReply := bob.readUntil(func(l string) bool {
+		return strings.Contains(l, " 302 ")
+	})
+	assertContains(
+		t, bobReply, " 302 ",
+		"RPL_USERHOST multi-nick",
+	)
+	assertContains(
+		t, bobReply, "alice",
+		"USERHOST multi contains alice",
+	)
+	assertContains(
+		t, bobReply, "bob",
+		"USERHOST multi contains bob",
+	)
+}
+
+// TestIntegrationVersion verifies the VERSION command
+// returns the server version string.
+func TestIntegrationVersion(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+
+	alice := env.dial(t)
+	alice.register("alice")
+
+	alice.send("VERSION")
+
+	aliceReply := alice.readUntil(func(l string) bool {
+		return strings.Contains(l, " 351 ")
+	})
+	assertContains(
+		t, aliceReply, " 351 ",
+		"RPL_VERSION",
+	)
+	assertContains(
+		t, aliceReply, "neoirc",
+		"VERSION reply contains server name",
+	)
+}
+
+// TestIntegrationAdmin verifies the ADMIN command returns
+// server admin info (256–259 numerics).
+func TestIntegrationAdmin(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+
+	alice := env.dial(t)
+	alice.register("alice")
+
+	alice.send("ADMIN")
+
+	aliceReply := alice.readUntil(func(l string) bool {
+		return strings.Contains(l, " 259 ")
+	})
+	assertContains(
+		t, aliceReply, " 256 ",
+		"RPL_ADMINME",
+	)
+	assertContains(
+		t, aliceReply, " 257 ",
+		"RPL_ADMINLOC1",
+	)
+	assertContains(
+		t, aliceReply, " 258 ",
+		"RPL_ADMINLOC2",
+	)
+	assertContains(
+		t, aliceReply, " 259 ",
+		"RPL_ADMINEMAIL",
+	)
+}
+
+// TestIntegrationInfo verifies the INFO command returns
+// server information (371/374 numerics).
+func TestIntegrationInfo(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+
+	alice := env.dial(t)
+	alice.register("alice")
+
+	alice.send("INFO")
+
+	aliceReply := alice.readUntil(func(l string) bool {
+		return strings.Contains(l, " 374 ")
+	})
+	assertContains(
+		t, aliceReply, " 371 ",
+		"RPL_INFO",
+	)
+	assertContains(
+		t, aliceReply, " 374 ",
+		"RPL_ENDOFINFO",
+	)
+	assertContains(
+		t, aliceReply, "neoirc",
+		"INFO reply mentions server name",
+	)
+}
+
+// TestIntegrationTime verifies the TIME command returns
+// the server time (391 numeric).
+func TestIntegrationTime(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnv(t)
+
+	alice := env.dial(t)
+	alice.register("alice")
+
+	alice.send("TIME")
+
+	aliceReply := alice.readUntil(func(l string) bool {
+		return strings.Contains(l, " 391 ")
+	})
+	assertContains(
+		t, aliceReply, " 391 ",
+		"RPL_TIME",
+	)
+	assertContains(
+		t, aliceReply, "test.irc",
+		"TIME reply includes server name",
+	)
+}
+
+// TestIntegrationKill verifies the KILL command: oper can
+// kill a user, non-oper cannot.
+func TestIntegrationKill(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnvWithOper(t)
+
+	alice := env.dial(t)
+	alice.register("alice")
+
+	bob := env.dial(t)
+	bob.register("bob")
+
+	// Both join a channel so KILL's QUIT is visible.
+	alice.joinAndDrain("#killtest")
+	bob.joinAndDrain("#killtest")
+
+	// Drain alice's view of bob's join.
+	alice.readUntil(func(l string) bool {
+		return strings.Contains(l, "JOIN") &&
+			strings.Contains(l, "bob")
+	})
+
+	// Non-oper KILL should fail.
+	alice.send("KILL bob :nope")
+
+	aliceKillFail := alice.readUntil(func(l string) bool {
+		return strings.Contains(l, " 481 ")
+	})
+	assertContains(
+		t, aliceKillFail, " 481 ",
+		"ERR_NOPRIVILEGES for non-oper KILL",
+	)
+
+	// alice becomes oper.
+	alice.send("OPER testoper testpass")
+	alice.readUntil(func(l string) bool {
+		return strings.Contains(l, " 381 ")
+	})
+
+	// Oper KILL should succeed.
+	alice.send("KILL bob :bad behavior")
+
+	// alice should see bob's QUIT relay.
+	aliceSeesQuit := alice.readUntil(func(l string) bool {
+		return strings.Contains(l, "QUIT") &&
+			strings.Contains(l, "bob")
+	})
+	assertContains(
+		t, aliceSeesQuit, "Killed",
+		"KILL reason in QUIT message",
+	)
+
+	// KILL nonexistent nick.
+	alice.send("KILL nobody123 :gone")
+
+	aliceNoSuch := alice.readUntil(func(l string) bool {
+		return strings.Contains(l, " 401 ")
+	})
+	assertContains(
+		t, aliceNoSuch, " 401 ",
+		"ERR_NOSUCHNICK for KILL missing target",
+	)
+}
+
+// TestIntegrationWallops verifies the WALLOPS command:
+// oper can broadcast to +w users.
+func TestIntegrationWallops(t *testing.T) {
+	t.Parallel()
+
+	env := newTestEnvWithOper(t)
+
+	alice := env.dial(t)
+	alice.register("alice")
+
+	bob := env.dial(t)
+	bob.register("bob")
+
+	// Non-oper WALLOPS should fail.
+	alice.send("WALLOPS :test broadcast")
+
+	aliceWallopsFail := alice.readUntil(func(l string) bool {
+		return strings.Contains(l, " 481 ")
+	})
+	assertContains(
+		t, aliceWallopsFail, " 481 ",
+		"ERR_NOPRIVILEGES for non-oper WALLOPS",
+	)
+
+	// alice becomes oper.
+	alice.send("OPER testoper testpass")
+	alice.readUntil(func(l string) bool {
+		return strings.Contains(l, " 381 ")
+	})
+
+	// bob sets +w to receive wallops.
+	bob.send("MODE bob +w")
+	bob.readUntil(func(l string) bool {
+		return strings.Contains(l, " 221 ")
+	})
+
+	// alice sends WALLOPS.
+	alice.send("WALLOPS :important announcement")
+
+	// bob (who has +w) should receive it.
+	bobWallops := bob.readUntil(func(l string) bool {
+		return strings.Contains(
+			l, "important announcement",
+		)
+	})
+	assertContains(
+		t, bobWallops, "important announcement",
+		"bob receives WALLOPS message",
+	)
+	assertContains(
+		t, bobWallops, "WALLOPS",
+		"message is WALLOPS command",
+	)
+}
+
 // TestIntegrationModeSecret tests +s (secret) channel
 // mode — verifies that +s can be set and the mode is
 // reflected in MODE queries.