waypointIconOrDefault

The icon to render for a waypoint, where 0 on the wire means "unset" and selects PUSHPIN_CODE_POINT.

Zero is a valid code point, so toCodePointString renders it as U+0000 rather than falling back. That matters because the trust-boundary clamp in MeshDataHandlerImpl normalises an unrenderable icon to 0 — every display and send path therefore has to read zero as the default rather than as a control character.