World props: town dressing

Model and bake the 123 sprites of group town of the world-props order (assets/requests/world-props/town.md, brief assets/requests/world-props.md) on their own branch. Done when every sprite of the list is in assets/manifest.d/world_town.toml, baked and reviewed on a gallery sheet.

All 123 are modelled (tools/blender/models/world_town/: stalls, goods, street, statues, signs, heraldry, garden, clutter, works on a group kit town_kit.py), baked on the texel lattice (every script's check_lattice() passes) and reviewed family by family on gallery sheets. Waiting for merge into feat/world-atlas.