Add optional name property to navigation.course.nextPoint

[msallin]

Problem

When navigating to a waypoint or along a route, navigation.course.nextPoint contains position, type, and href, but no human-readable name for the destination point.

Waypoint resources already have name?: string, and route points have names via coordinatesMeta[].name (a required field). But this information is not part of the nextPoint schema, so consumers like NMEA 0183 sentence generators cannot include the waypoint identifier in sentences like APB (field 10) or RMB (fields 4-5).

Proposed change

Add an optional name string property to the nextPoint (and previousPoint) schema in schemas/groups/navigation.json:

"name": {
  "type": "string",
  "description": "Human-readable name or identifier of the point, as provided by the waypoint resource or route point metadata."
}

Context

• NMEA 0183 APB field 10 (Destination Waypoint ID) requires a waypoint identifier. Without a name in the SK data model, generators must hardcode a placeholder.
• The server already fetches waypoint resources and route metadata that contain names, but has no spec-defined field to put them in.
• Related server issue to follow for the implementation side.