Echo of Nothingness

# Changelog 
## New
- New creature — Hushrot Sheep: a low-tier infected that grazes grass and plants to heal itself and gain biomass
- New creature — Mad Husk: an Ascended-tier mob with leaping dash, triple cleave (multi-hit), dark roar and a half-HP rage; evolves from the Empty Shell
- New effect — Fury: +25% all damage and +15% movement speed per level; void creatures additionally gain -10% skill cooldown per level (up to -60%); players additionally gain attack-speed and bow-draw bonuses
- Global void settings: void creature health / attack / true-damage multipliers, and the void-mass conversion chance for creatures with no fixed form

## Mechanics & Balance
- Void Infection reworked: damage formula updated (0.75 × level/s; (0.75 + 0.25% current HP) × level/s at high health; halved against players); execute threshold lowered to 10% + 10% × level; max level raised to 8
- Tear reworked: movement damage is now (0.5 + 0.05% current HP) × level per 0.1 m moved; halved against players
- Creatures killed by void creatures now trigger assimilation: fixed forms convert 100%, the rest turn into Void Mass by chance
- Jiran Spike: collapse only triggers from light sources; growth speed is affected by light; 4-block growth spacing; 3x3 fall detection
- Lesser Remains corrupt the 3x3 below; Cystoids splash ichor when bursting; the Deep Dark Vine blooms into a Deep Dark Lotus with a 50% chance when it hits a solid block
- Infected creatures now self-destruct and leave remains — trigger chance: 10% (Basic) / 20% (Low)

## Visuals & Fixes
- Void stain fixed and brightened (grass blocks, leaves, grass, ferns)
- Spawn eggs unified to the vanilla style, with fixed sorting
- Slightly increased the Giant Jiran Creeper's model size
- Improved the textures of the Giant Jiran Creeper and the Ender Herald