Replaces PlayerMovementController's ad-hoc airborne-only reflect + Velocity.Z landing
snap with the verbatim retail chain: cached_velocity = (resolved-old)/dt (separate
reporting value), SetPositionInternal contact determination (kept Velocity.Z<=0 gate for
acdream's always-step-down resolver), then handle_all_collisions (fsf<=1 reflect / fsf>1
zero — the airborne-stuck bleed). Contact is committed BEFORE the reflect so the landing
gate isn't defeated by a reflected +Z; that ordering + the ungated small-velocity-zero
(Slice 1a) retire AD-25's micro-bounce spiral.
Load-bearing: handle_all_collisions + cached_velocity are gated on candidateMoved (retail
UpdateObjectInternal pc:283657 only reaches SetPositionInternal when the integrated
candidate moved off m_position). After fsf>1 zeros a blocked jump, the next frame
integrates zero motion (velMag2==0), so the candidate hasn't moved — skipping the response
that frame lets gravity rebuild the velocity instead of re-zeroing it and re-wedging.
End-to-end Core test (Issue182CrowdJumpTests): a jump blocked by an overhead creature
bleeds its +12 up-velocity to ~0 within a couple frames (fsf>1) and the body grounds on
the manufactured plane instead of hanging with persistent +12. Core 2617 / App 741 green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>