Tab-toggled player mode with WASD ground walking, A/D + mouse
turning, Z/X strafing, Shift for run, third-person chase camera,
local walk/run/turn/idle animations, and outbound MoveToState +
AutonomousPosition server messages. Uses PhysicsEngine from B.3
for collision-resolved positions.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
