Enable physics ragdoll and apply explosion impulse

Pattern: OnDeath → GetMesh → SetSimulatePhysics(bSimulate=true) → AddImpulse(Impulse=MakeVector(X=0,Y=0,Z=500), bVelChange=true). For explosion: GetMesh → AddRadialImpulse(Origin=ExplosionLocation, Radius=500, Strength=1000, Falloff=RIF_Linear, bVelChange=false). Key: Always call SetSimulatePhysics BEFORE AddImpulse. AddImpulse input 'bVelChange=true' for direct velocity (ignores mass). AddRadialImpulse is on PrimitiveComponent.