FIRST LIGHT map authoring

The circuit catalogue lives at rainline/maps/catalog.module/init.luau. It defines five independent closed layouts, names, descriptions, biome and road half-width. rainline.shared builds their smooth paths, and rainline.visuals.circuit produces the road, barriers, details and lighting.

Use in edit mode:

1. tools.use("firstLightMaps","inspect",4) — inspect length, bounds and source points.
2. tools.use("firstLightMaps","setLayout",4,points) — save an ordered array of {x,z} points. Use 6–80 points at least24m apart. Coordinates exclude the circuit's world offset. Crossing control polygons are rejected.
3. tools.use("firstLightMaps","rebuild",4) — switch to that circuit as the root editing scene, rebuild and save it.
4. tools.use("scene","load","scenes.rainline") — return to the multiplayer game.

Always inspect the smoothed result from above and road height. Polygon validation does not prove spline/road clearance. Rebuild after changing catalogue parameters or circuit set dressing. Preserve literal references when extending StageLoader with a new stage. The menu paginates the catalogue automatically. Stage content stays unloaded until selected.

Black Quarry uses biome3 rock cuts without the forest canopy; Saltspan uses biome1 with an open-water viaduct instead of an infield. Their structural detail is authored in circuit.sceneModule, alongside the reusable apron props, tar seams, drainage and road fixtures.