Obstacles and obstructions draw green, as APP-06 8.1.4.3 requires, and the
decoration layout that surfaced while getting there.

A minor, not a major: nothing is removed or renamed, no types change, and the two
new config fields are optional — a consumer that never touches them compiles and
runs unchanged. But 35 graphics change colour without any code change on their
part, so the changelog entry leads with that rather than burying it, and says how
to keep the old appearance in one line.

Pre-flight: npm audit 0 for production and 0 across the whole tree, the first
release where the development half is clean too; 34 packages in the closure, 32
MIT with one 0BSD and one Unlicense, no copyleft; tracker current at 317 graphics
and 330 variants.