Getters that return pointers into shared thread-local storage

[jcant0n]

Several getters return const T* pointing at a thread_local snapshot rather than at the object's own data. A second call on the same thread overwrites the first result, so a = Get(x); b = Get(y); leaves both showing y.

Confirmed cases:

function	what is shared
Skeleton_GetJoint	joint->name and parentName point into two thread_local std::strings
Ragdoll_GetRagdollSettings	returns &tl_rs, one static thread_local wrapper for every ragdoll
WheelSettingsWV_GetLongitudinalFriction / GetLateralFriction	shared snapshot
WheeledVehicleController_GetTransmission and the settings equivalent	shared snapshot

The const T* signature reads like a borrowed reference to live data. It is a copy with a lifetime of "until the next call on this thread", and nothing in the headers says so.

This bites hardest in a managed layer. A C# binding that copies the struct and marshals the strings later reads whichever name was fetched most recently — the failure is a wrong value, not a crash, and it will look like a data bug anywhere but here.

Ragdoll_GetRagdollSettings has a second edge: passing its result to RagdollSettings_Destroy would drop a reference the Ragdoll still owns. Only a comment prevents that today.

The tests in test_skeleton_extra.c and test_vehicle_extra.c read each result before the next call, which is a workaround rather than a fix.