Function resolveTerrainConfig

resolveTerrainConfig(
definition: BasemapDefinition,
key: string,
): TerrainConfig | null
Extracts the TerrainConfig from a basemap definition if it is valid and enabled.

Performs boot-time validation:
- Logs an error if terrain.enabled is true but terrain.demUrl is missing.
Parameters
- definition: BasemapDefinition
  The basemap config object from the registry.
- key: string
  The basemap key (for log messages).
Returns TerrainConfig | null
The TerrainConfig if valid and enabled, otherwise null.
- Defined in src/kernel/basemaps/terrain.ts:201