init.lua loads the work map, binds hotkeys (E/R/S/Esc), tracks
mouse-cell per frame, dispatches clicks to the UI hit-tester
and falls through to paint-cell for unconsumed map-area clicks.
run-map-editor.sh handles copy-in/copy-out for a real target map
or runs in-place against the module's work slot.
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.