URL template with {z}/{x}/{y} placeholders (and optional {s} subdomain).
OptionalmaxDeepest native zoom. Default 19.
OptionaltileTile edge in px. Default 256.
OptionalsubdomainsHost shards cycled through {s} (spreads load; deterministic per tile so the
browser/persistent cache still hits).
Options for xyzImagery, a generic
{z}/{x}/{y}slippy-map source.