fix(movement): jump works locally (airborne velocity preserved)

Two fixes for jump physics:
- Skip ground-snap when velocity Z > 0 (prevents immediate re-landing
  at high framerates where per-frame Z delta < 0.05 snap threshold)
- Guard apply_current_movement velocity write behind OnWalkable check
  (prevents MotionInterpreter.DoMotion from zeroing jump velocity on
  every frame while airborne)
- Guard PlayerMovementController velocity replacement behind OnWalkable
  (preserves momentum during airborne flight)

Also fix run speed: compute RunRate locally via PlayerWeenie.InqRunRate
instead of waiting for server UpdateMotion echo (server doesn't echo
to sender). With Run skill 200, run speed is now 9.5 m/s instead of
4.0 m/s.

Strip all diagnostic logging from previous debug sessions.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/AcDream.App/Rendering/GameWindow.cs

@@ -967,7 +967,6 @@ public sealed class GameWindow : IDisposable
             && update.MotionState.ForwardSpeed.HasValue
             && update.MotionState.ForwardSpeed.Value > 0f)
         {
-            Console.WriteLine($"DEBUG RunRate: guid={update.Guid:X8} fwd={update.MotionState.ForwardSpeed.Value:F3}");
             _playerController.ApplyServerRunRate(update.MotionState.ForwardSpeed.Value);
         }