Constraintcore bone functions select wrong bones

[Darmagon3]

Describe the bug

Any attempt to weld, nocollide, rope, slider, or hydraulic a ragdoll bone will always target bone 0
All constraintcore functions involving bones use local ent, index = isValidBone(bone) to acquire the bone index
isValidBone(b) always returns a second value of 0 or nil, so the bone index is always 0 or nil.

How to reproduce the bug

Create an E2 that targets and constrains a bone of a ragdoll other than bone 0.
If this E2 attempts to constrain bone 0, the bug has occurred.

An example E2 is provided:

@name bugreport/constraintcore_wrong_bone
@strict

Entity = entity():isConstrainedTo() #put this E2 on a ragdoll
Bone1 = Entity:bone(1)
Bone2 = Entity:bone(2)
Bone1:weld(Bone2) #Weld bone 1 to bone 2
#Constraint creation failed!
#This actually welds bone 0 to bone 0, constraint creation will always fail.