fix: harden address parsing edge cases

common/globals_test.go

@@ -0,0 +1,10 @@
+package common
+
+import "testing"
+
+func TestHostInfoTargetUsesBracketedIPv6(t *testing.T) {
+	info := &HostInfo{Host: "2001:db8::1", Port: 443}
+	if got, want := info.Target(), "[2001:db8::1]:443"; got != want {
+		t.Fatalf("Target() = %q, want %q", got, want)
+	}
+}