Add new damage modifier for explosives

[Agiel]

Description

Adds a new damage modifier for explosives sv_neo_exp_dmg_modifier with the same default value as the weapon modifier (1.485, which is parity).

I made it a separate modifier because I can see scenarios where we want to reduce bullet damage without affecting the grenades. The modifier is applied pretty high up the chain, because CGameRules::RadiusDamage takes the damage info as a const, and we want the correct damage in the WeaponHit event.

Note that explosives can still do less damage than they would in OGNT if there's a prop between the player and the explosion. This is intentional (by Valve) and handled in CGameRules::RadiusDamage. I deemed it outside the scope of this issue.

Toolchain

• Cachy OS - gcc version 16.2.1 20260810

Linked Issues

• fixes Explosives should be affected by the damage multiplier #2076

[AdamTadeusz]

on devbox tested with a recon, throwing a grenade near straight down

Throw Position
bind k "setpos 0 0 180; setang 90 0 0"
Taking Damage Position
bind l "setpos 256 0 180; setang 90 0 0"

left with 88HP in both og and this branch, on master it was more like 92