- Acid now uses acid_resist + health-based damage (not instant delete)
- Acid dissolve speeds: Wood ~2s, Dirt ~2.8s, Stone ~4.3s, Iron immune
- New material: Iron (ID 16) - silver, static, acid-proof, heat-conductive
- Iron texture: bright highlights for metallic shine
- Iron reflects light (light_block: 150)
- Iron heat_conduct: 200 - conducts heat quickly through entire block
- Improved heat transfer formula (divisor 255→200)
- Updated AGENTS.md status
- No player code (rolled back for fresh start)
nico
26d5733e1e