CI / quality (push) Successful in 54s
- New shared Chassis.luau: geometry constants + per-car tuning from stats - CarManager.buildCarModel rebuilt: prismatic+spring suspension per corner, servo-hinge steering on front knuckles, motor-hinge driven wheels, hidden dense ballast for anti-roll; VehicleSeat kept as input device only - New client ChassisController: drives motors/servos from seat ThrottleFloat/SteerFloat per Heartbeat; speed-sensitive steering lock; engine braking on throttle release - Driver gets network ownership of every unanchored part (constraint assemblies are separate; missing one causes stuttery physics) - Docs: MESH_SWAP.md rewritten for shell-on-chassis workflow; ROADMAP updated