Voxel people, block signs and prototype lighting

[anwarselo]

Characters, workers, signs and lighting now follow the Voxel Software Factory prototype.

• People and AI workers share one blocky model (big square head, face, hair, trim, sleeves, hands, legs) with baked ambient occlusion and per-block colour jitter. Shirt, skin and hair still take the player's colours.
• Name tags, task cards, speech bubbles and board/arcade/cabinet signs are hard-edged with a stepped shadow and ink outline; the need-you pin and note pin are square.
• Lighting: warm sun with softer shadows, a cool fill light from the shaded side, prototype hemisphere colours, slightly brighter exposure.

First-person hands are unchanged (separate articulated rig).

Checks: typecheck, npm test (653 pass), npm run build. Looked at the live build in the browser (seated workers, signs, shading).