Towns from rectangular districts

Every town was a circle (walled ones an octagon), which tiles can't draw, and they all looked alike. Done when towns are built from rectangular districts in varied shapes, each with its own street structure, walls follow the outline, and the town tests still hold.

Done: eight shapes fitted to the ground, a street grid per district, district roles, walls with chamfered corners and gates on straight runs, the ground blend by distance to the outline.