Scaffold sporel-module-map-editor package

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.

maps/work.map.json

@@ -0,0 +1,11 @@
+{
+  "schema_version": 2,
+  "id": "work",
+  "size": { "w": 4, "h": 4 },
+  "atlases": ["fa_terrain_v1"],
+  "layers": {
+    "surface": {
+      "tiles": [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
+    }
+  }
+}