Other module manifests (spine-prototype, vagrant-skeleton, etc.) use
the short directory name as the id, not the long 'sporel-module-X'
form which is reserved for the Gitea slug. The mismatch caused the
launcher script (which exports SPOREL_MODULE=map-editor) to fail
with ENGINE_ERR_MODULE_NOT_FOUND.
Empty launchable module with deps on lib-core.maps 0.4.0, render,
camera, input, and the fa_terrain_v1 asset alias. Renders the
default 4x4 empty work-map; interactive editing wired in
subsequent commits.
