Itaverax Segmented Unit Immunity

A temporary stopgap mod that fixes vanilla demolishers (and other
segmented-unit/segment prototype enemies) self-destructing on Vulcanus
when running alongside Abacayba: Infested Death Twin of Nauvis.

The problem

Abacayba applies a bonus melee damage type (itaverax) to all
SegmentedUnitPrototype entities in the game, not just its own new content.
Vanilla demolisher resistances were authored before the itaverax damage
type existed, so they have no resistance entry for it and take full,
unmitigated self-inflicted damage from their own attacks -- draining to
death on their own, even completely undisturbed.

The fix

This mod runs in data-final-fixes.lua (after every other mod's data
stage) and grants 100% itaverax resistance to every segmented-unit and
segment prototype in the game, mirroring how broadly Abacayba itself
applies the damage type. It will not override an existing resistance entry
if one is already present.

Status

This is a stopgap only. Abacayba's author (emerson5442) is aware of the
underlying issue and intends to ship a proper fix in a future Abacayba
update. Once that lands, this mod can be disabled or removed.