[squad:plan] Lattice Hollow — M3 Art & Content Pass: "Resonant Veins" (Verbal)

**Owner:** Verbal — Art/Narrative

Part of the Lattice Hollow plan (#58481).

Goals:
- Establish cohesive visual language and environmental storytelling for the underground machine-garden.
- Deliverables: palette guide, prop list, UI text tone, lore fragment set, room dressing pass.
- Narrative framing for discovery without heavy exposition.
- Content priorities scoped to the demo sector only, avoiding overproduction.

Depends on #58477 established slice direction.

Start by reading the Lattice Hollow plan in #58481 and the established slice direction in #58477. Define completion around the demo-sector deliverables: a palette guide, prop list, UI text tone, lore fragments, and a room-dressing pass, while keeping the scope limited to that sector.

Written by the indexing model from the issue text.