Per the B.6 design spec (now retail-grounded on Option A), slice 1 is
pure-additive logging so the next session has a clean trace of what
ACE actually sends to the local player during a server-initiated
auto-walk.
New PhysicsDiagnostics.ProbeAutoWalkEnabled static flag, env-var-
initialized from ACDREAM_PROBE_AUTOWALK=1. Probe sites:
[autowalk-out] on SendUse + SendPickUp — the packets that trigger
ACE's CreateMoveToChain when the target is out of WithinUseRadius.
[autowalk-mt] on OnLiveMotionUpdated for _playerServerGuid only —
captures MovementType + MoveToPath origin/min-dist/obj-dist +
moveTowards + speed/runRate. Lets us see exactly the wire data
retail's PerformMovement case 6 (0x00524440) was acting on.
[autowalk-up] on OnLivePositionUpdated for _playerServerGuid only —
cadence + payload of ACE's position broadcasts during auto-walk.
No behavior change. All flags off by default; opt in with the env var
during a focused reproduction. Designed to be mirrored into DebugVM
checkbox state later (parallel to ProbeResolve / ProbeCell / ProbeBuilding)
but not wired yet — env-var-only for the first trace session.