K-fix11 (150 ms exponential lag) wasn't aggressive enough — at
0.15 s time constant the camera catches up to ~96 % of the
player's Z before peak, so the visible "rise on screen" was
maybe ~0.5 m of the 3.11 m arc. User reported the jump still
looked short.
K-fix12: replace the lag with an explicit airborne-pin. The
camera's tracked Z follows player Z directly while grounded,
but stays PINNED while airborne and rising. Falling / dropping
catches up immediately so we don't end up below ground when
landing in a hole.
Effect: during a jump the player visibly rises 3 m above the
camera on screen, matching retail's "you can see yourself jump"
feel. After landing the camera's tracked Z snaps back to the
player Z so there's no lingering vertical offset.
ChaseCamera.Update gains an isOnGround parameter; GameWindow
passes result.IsOnGround from the per-frame movement controller.
The look-at point still uses raw player Z so the camera tilts up
to keep the airborne character framed.
Tests stay 1222 green.
4b6fcffa01